Convert.ToInt16 方法

定义

将指定的值转换为 16 位有符号整数。

重载

ToInt16(String, Int32)

将指定基数的数字的字符串表示形式转换为等效的 16 位有符号整数。

ToInt16(String, IFormatProvider)

使用指定的区域性特定格式设置信息,将数字的指定字符串表示形式转换为等效的 16 位带符号整数。

ToInt16(Object, IFormatProvider)

使用指定的区域性特定格式信息,将指定对象的值转换为 16 位带符号整数。

ToInt16(UInt64)

将指定的 64 位无符号整数的值转换为等效的 16 位有符号整数。

ToInt16(UInt32)

将指定的 32 位无符号整数的值转换为等效的 16 位有符号整数。

ToInt16(UInt16)

将指定的 16 位无符号整数的值转换为等效的 16 位有符号整数。

ToInt16(String)

将数字的指定字符串表示形式转换为等效的 16 位带符号整数。

ToInt16(Single)

将指定的单精度浮点数的值转换为等效的 16 位带符号整数。

ToInt16(SByte)

将指定的 8 位带符号整数的值转换为等效的 16 位带符号整数。

ToInt16(Int32)

将指定的 32 位有符号整数的值转换为等效的 16 位有符号整数。

ToInt16(Int64)

将指定的 64 位有符号整数的值转换为等效的 16 位有符号整数。

ToInt16(Int16)

返回指定的 16 位有符号整数;不执行实际的转换。

ToInt16(Double)

将指定的双精度浮点数的值转换为等效的 16 位带符号整数。

ToInt16(Decimal)

将指定的十进制数的值转换为等效的 16 位带符号整数。

ToInt16(DateTime)

调用此方法始终引发 InvalidCastException

ToInt16(Char)

将指定的 Unicode 字符的值转换为等效的 16 位有符号整数。

ToInt16(Byte)

将指定的 8 位无符号整数的值转换为等效的 16 位有符号整数。

ToInt16(Boolean)

将指定的布尔值转换为等效的 16 位带符号整数。

ToInt16(Object)

将指定对象的值转换为 16 位带符号整数。

ToInt16(String, Int32)

将指定基数的数字的字符串表示形式转换为等效的 16 位有符号整数。

public:
 static short ToInt16(System::String ^ value, int fromBase);
public static short ToInt16 (string value, int fromBase);
public static short ToInt16 (string? value, int fromBase);
static member ToInt16 : string * int -> int16
Public Shared Function ToInt16 (value As String, fromBase As Integer) As Short

参数

value
String

包含要转换的数字的字符串。

fromBase
Int32

value 中数字的基数,它必须是 2、8、10 或 16。

返回

Int16

一个与 value 中数字等效的 16 位带符号整数,如果 valuenull,则为 0(零)。

例外

fromBase 不是 2、8、10 或 16。

  • 或 -

value(表示基数不为 10 的符号数字)的前缀为负号。

value 上声明的默认值为 Empty

value 包含一个字符,该字符不是由 fromBase 指定的基数中的有效数字。 如果 value 中的第一个字符无效,则该异常消息指示没有要转换的数字;否则,该消息指示 value 包含无效的尾随字符。

value(表示基数不为 10 的符号数字)的前缀为负号。

  • 或 -

value表示小于 Int16.MinValue 或大于 Int16.MaxValue 的数字MaxValue

示例

以下示例尝试将字符串数组中的每个元素解释为十六进制字符串,并将其转换为 16 位带符号整数。

using System;

public class Example
{
   public static void Main()
   {
      string[] hexStrings = { "8000", "0FFF", "f000", "00A30", "D", "-13",
                              "9AC61", "GAD" };
      foreach (string hexString in hexStrings)
      {
         try {
            short number = Convert.ToInt16(hexString, 16);
            Console.WriteLine("Converted '{0}' to {1:N0}.", hexString, number);
         }
         catch (FormatException) {
            Console.WriteLine("'{0}' is not in the correct format for a hexadecimal number.",
                              hexString);
         }
         catch (OverflowException) {
            Console.WriteLine("'{0}' is outside the range of an Int16.", hexString);
         }
         catch (ArgumentException) {
            Console.WriteLine("'{0}' is invalid in base 16.", hexString);
         }
      }
   }
}
// The example displays the following output:
//       Converted '8000' to -32,768.
//       Converted '0FFF' to 4,095.
//       Converted 'f000' to -4,096.
//       Converted '00A30' to 2,608.
//       Converted 'D' to 13.
//       '-13' is invalid in base 16.
//       '9AC61' is outside the range of an Int16.
//       'GAD' is not in the correct format for a hexadecimal number.
open System

let hexStrings = 
    [| "8000"; "0FFF"; "f000"; "00A30"
       "D"; "-13"; "9AC61"; "GAD" |]

for hexString in hexStrings do
    try
        let number = Convert.ToInt16(hexString, 16)
        printfn $"Converted '{hexString}' to {number:N0}."
    with
    | :? FormatException ->
        printfn $"'{hexString}' is not in the correct format for a hexadecimal number."
    | :? OverflowException ->
        printfn $"'{hexString}' is outside the range of an Int16."
    | :? ArgumentException ->
        printfn $"'{hexString}' is invalid in base 16."
// The example displays the following output:
//       Converted '8000' to -32,768.
//       Converted '0FFF' to 4,095.
//       Converted 'f000' to -4,096.
//       Converted '00A30' to 2,608.
//       Converted 'D' to 13.
//       '-13' is invalid in base 16.
//       '9AC61' is outside the range of an Int16.
//       'GAD' is not in the correct format for a hexadecimal number.
Module Example
   Public Sub Main()
      Dim hexStrings() As String = { "8000", "0FFF", "f000", "00A30", "D", _
                                     "-13", "9AC61", "GAD" }
      For Each hexString As String In hexStrings
         Try
            Dim number As Short = Convert.ToInt16(hexString, 16)
            Console.WriteLine("Converted '{0}' to {1:N0}.", hexString, number)
         Catch e As FormatException
            Console.WriteLine("'{0}' is not in the correct format for a hexadecimal number.", _
                              hexString)
         Catch e As OverflowException
            Console.WriteLine("'{0}' is outside the range of an Int16.", hexString)
         Catch e As ArgumentException
            Console.WriteLine("'{0}' is invalid in base 16.", hexString)
         End Try
      Next                                            
   End Sub
End Module
' The example displays the following output:
'       Converted '8000' to -32,768.
'       Converted '0FFF' to 4,095.
'       Converted 'f000' to -4,096.
'       Converted '00A30' to 2,608.
'       Converted 'D' to 13.
'       '-13' is invalid in base 16.
'       '9AC61' is outside the range of an Int16.
'       'GAD' is not in the correct format for a hexadecimal number.

注解

如果 fromBase 为 16,则可以将参数指定的 value 数字前缀为“0x”或“0X”。

由于非基 10 数值表示形式不支持负号,因此该方法 ToInt16(String, Int32) 假定负数使用两个的补数表示形式。 换句话说,该方法始终将整数 (位 15 位) 的最高顺序二进制位解释为其符号位。 因此,可以编写代码,其中非基 10 数字在数据类型范围 Int16 之外转换为 Int16 值而不引发异常的方法。 以下示例按一个递增 Int16.MaxValue ,将生成的数字转换为其十六进制字符串表示形式,然后调用 ToInt16(String, Int32) 该方法。 该方法不引发异常,而是显示消息“0x8000转换为 -32768”。

// Create a hexadecimal value out of range of the Int16 type.
string value = Convert.ToString((int) short.MaxValue + 1, 16);
// Convert it back to a number.
try
{
   short number = Convert.ToInt16(value, 16);
   Console.WriteLine("0x{0} converts to {1}.", value, number);
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a 16-bit integer.", value);
}
// Create a hexadecimal value out of range of the Int16 type.
let value = Convert.ToString(int Int16.MaxValue + 1, 16)
// Convert it back to a number.
try
    let number = Convert.ToInt16(value, 16)
    printfn $"0x{value} converts to {number}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to a 16-bit integer."
' Create a hexadecimal value out of range of the Int16 type.
Dim value As String = Convert.ToString(CInt(Short.MaxValue) + 1, 16)
' Convert it back to a number.
Try
   Dim number As Short = Convert.ToInt16(value, 16)
   Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a 16-bit integer.", value)
End Try

执行二进制操作或数字转换时,开发人员始终有责任验证方法是否使用适当的数字表示形式来解释特定值。 如以下示例所示,可以确保在将数值转换为其十六进制字符串表示形式之前先检索数值的符号来适当处理溢出。 如果原始值为正值,但转换回整数会生成负值,则引发异常。

// Create a hexadecimal value out of range of the Short type.
int sourceNumber = (int) short.MaxValue + 1;
bool isNegative = (Math.Sign(sourceNumber) == -1);
string value = Convert.ToString(sourceNumber, 16);
short targetNumber;
try
{
   targetNumber = Convert.ToInt16(value, 16);
   if (! isNegative && ((targetNumber & 0x8000) != 0))
      throw new OverflowException();
   else
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber);
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a 16-bit integer.", value);
}
// Displays the following to the console:
//    Unable to convert '0x8000' to a 16-bit integer.
// Create a hexadecimal value out of range of the Short type.
let sourceNumber = int Int16.MaxValue + 1
let isNegative = sign sourceNumber = -1
let value = Convert.ToString(sourceNumber, 16)
try
    let targetNumber = Convert.ToInt16(value, 16)
    if not isNegative && targetNumber &&& 0x8000s <> 0s then
        raise (OverflowException())
    else
        printfn $"0x{value} converts to {targetNumber}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to a 16-bit integer."
// Displays the following to the console:
//    Unable to convert '0x8000' to a 16-bit integer.
' Create a hexadecimal value out of range of the Short type.
Dim sourceNumber As Integer = CInt(Short.MaxValue) + 1
Dim isNegative As Boolean = (Math.Sign(sourceNumber) = -1)
Dim value As String = Convert.ToString(sourceNumber, 16)
Dim targetNumber As Short
Try
   targetNumber = Convert.ToInt16(value, 16)
   If Not isNegative And ((targetNumber And &H8000) <> 0) Then
      Throw New OverflowException()
   Else 
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber)
   End If    
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a 16-bit integer.", value)
End Try 
' Displays the following to the console:
'    Unable to convert '0x8000' to a 16-bit integer.

适用于

ToInt16(String, IFormatProvider)

使用指定的区域性特定格式设置信息,将数字的指定字符串表示形式转换为等效的 16 位带符号整数。

public:
 static short ToInt16(System::String ^ value, IFormatProvider ^ provider);
public static short ToInt16 (string value, IFormatProvider provider);
public static short ToInt16 (string? value, IFormatProvider? provider);
static member ToInt16 : string * IFormatProvider -> int16
Public Shared Function ToInt16 (value As String, provider As IFormatProvider) As Short

参数

value
String

包含要转换的数字的字符串。

provider
IFormatProvider

一个提供区域性特定的格式设置信息的对象。

返回

Int16

一个与 value 中数字等效的 16 位带符号整数,如果 valuenull,则为 0(零)。

例外

value 不由一个可选符号后跟一系列数字 (0-9) 组成。

示例

以下示例使用IFormatProvider对象将 16 位整数的字符串表示形式与ToInt16方法转换。

// Example of the Convert::ToInt16( String* ) and 
// Convert::ToInt16( String*, IFormatProvider* ) methods.
using namespace System;
using namespace System::Globalization;
const __wchar_t * protoFmt = L"{0,-20}{1,-20}{2}";

// Get the exception type name; remove the namespace prefix.
String^ GetExceptionType( Exception^ ex )
{
   String^ exceptionType = ex->GetType()->ToString();
   return exceptionType->Substring( exceptionType->LastIndexOf( '.' ) + 1 );
}

void ConvertToInt16( String^ numericStr, IFormatProvider^ provider )
{
   Object^ defaultValue;
   Object^ providerValue;
   
   // Convert numericStr to Int16 without a format provider.
   try
   {
      defaultValue = Convert::ToInt16( numericStr );
   }
   catch ( Exception^ ex ) 
   {
      defaultValue = GetExceptionType( ex );
   }

   
   // Convert numericStr to Int16 with a format provider.
   try
   {
      providerValue = Convert::ToInt16( numericStr, provider );
   }
   catch ( Exception^ ex ) 
   {
      providerValue = GetExceptionType( ex );
   }

   Console::WriteLine( gcnew String( protoFmt ), numericStr, defaultValue, providerValue );
}

int main()
{
   
   // Create a NumberFormatInfo object and set several of its
   // properties that apply to numbers.
   NumberFormatInfo^ provider = gcnew NumberFormatInfo;
   
   // These properties affect the conversion.
   provider->NegativeSign = "neg ";
   provider->PositiveSign = "pos ";
   
   // These properties do not affect the conversion.
   // The input string cannot have decimal and group separators.
   provider->NumberDecimalSeparator = ".";
   provider->NumberGroupSeparator = ",";
   array<Int32>^sizes = {3};
   provider->NumberGroupSizes = sizes;
   provider->NumberNegativePattern = 0;
   Console::WriteLine( "This example of\n"
   "  Convert::ToInt16( String* ) and \n"
   "  Convert::ToInt16( String*, IFormatProvider* ) "
   "\ngenerates the following output. It converts "
   "several strings to \nshort values, using "
   "default formatting or a NumberFormatInfo object.\n" );
   Console::WriteLine( gcnew String( protoFmt ), "String to convert", "Default/exception", "Provider/exception" );
   Console::WriteLine( gcnew String( protoFmt ), "-----------------", "-----------------", "------------------" );
   
   // Convert strings, with and without an IFormatProvider.
   ConvertToInt16( "12345", provider );
   ConvertToInt16( "+12345", provider );
   ConvertToInt16( "pos 12345", provider );
   ConvertToInt16( "-12345", provider );
   ConvertToInt16( "neg 12345", provider );
   ConvertToInt16( "12345.", provider );
   ConvertToInt16( "12,345", provider );
   ConvertToInt16( "(12345)", provider );
   ConvertToInt16( "32768", provider );
   ConvertToInt16( "-32769", provider );
}

/*
This example of
  Convert::ToInt16( String* ) and
  Convert::ToInt16( String*, IFormatProvider* )
generates the following output. It converts several strings to
short values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
12345               12345               12345
+12345              12345               FormatException
pos 12345           FormatException     12345
-12345              -12345              FormatException
neg 12345           FormatException     -12345
12345.              FormatException     FormatException
12,345              FormatException     FormatException
(12345)             FormatException     FormatException
32768               OverflowException   OverflowException
-32769              OverflowException   FormatException
*/
// Example of the Convert.ToInt16( string ) and
// Convert.ToInt16( string, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToInt16ProviderDemo
{
    static string format = "{0,-20}{1,-20}{2}";

     // Get the exception type name; remove the namespace prefix.
    static string GetExceptionType( Exception ex )
    {
        string exceptionType = ex.GetType( ).ToString( );
        return exceptionType.Substring(
            exceptionType.LastIndexOf( '.' ) + 1 );
    }

    static void ConvertToInt16( string numericStr,
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

        // Convert numericStr to Int16 without a format provider.
        try
        {
            defaultValue = Convert.ToInt16( numericStr );
        }
        catch( Exception ex )
        {
            defaultValue = GetExceptionType( ex );
        }

        // Convert numericStr to Int16 with a format provider.
        try
        {
            providerValue = Convert.ToInt16( numericStr, provider );
        }
        catch( Exception ex )
        {
            providerValue = GetExceptionType( ex );
        }

        Console.WriteLine( format, numericStr,
            defaultValue, providerValue );
    }

    public static void Main( )
    {
        // Create a NumberFormatInfo object and set several of its
        // properties that apply to numbers.
        NumberFormatInfo provider = new NumberFormatInfo();

        // These properties affect the conversion.
        provider.NegativeSign = "neg ";
        provider.PositiveSign = "pos ";

        // These properties do not affect the conversion.
        // The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = ".";
        provider.NumberGroupSeparator = ",";
        provider.NumberGroupSizes = new int[ ] { 3 };
        provider.NumberNegativePattern = 0;

        Console.WriteLine("This example of\n" +
            "  Convert.ToInt16( string ) and \n" +
            "  Convert.ToInt16( string, IFormatProvider ) " +
            "\ngenerates the following output. It converts " +
            "several strings to \nshort values, using " +
            "default formatting or a NumberFormatInfo object.\n" );
        Console.WriteLine( format, "String to convert",
            "Default/exception", "Provider/exception" );
        Console.WriteLine( format, "-----------------",
            "-----------------", "------------------" );

        // Convert strings, with and without an IFormatProvider.
        ConvertToInt16( "12345", provider );
        ConvertToInt16( "+12345", provider );
        ConvertToInt16( "pos 12345", provider );
        ConvertToInt16( "-12345", provider );
        ConvertToInt16( "neg 12345", provider );
        ConvertToInt16( "12345.", provider );
        ConvertToInt16( "12,345", provider );
        ConvertToInt16( "(12345)", provider );
        ConvertToInt16( "32768", provider );
        ConvertToInt16( "-32769", provider );
    }
}

/*
This example of
  Convert.ToInt16( string ) and
  Convert.ToInt16( string, IFormatProvider )
generates the following output. It converts several strings to
short values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
12345               12345               12345
+12345              12345               FormatException
pos 12345           FormatException     12345
-12345              -12345              FormatException
neg 12345           FormatException     -12345
12345.              FormatException     FormatException
12,345              FormatException     FormatException
(12345)             FormatException     FormatException
32768               OverflowException   OverflowException
-32769              OverflowException   FormatException
*/
// Example of the Convert.ToInt16( string ) and
// Convert.ToInt16( string, IFormatProvider ) methods.
open System
open System.Globalization

let format obj1 obj2 obj3 = printfn $"{obj1,-20}{obj2,-20}{obj3}"

// Get the exception type name; remove the namespace prefix.
let getExceptionType (ex: exn) =
    let exceptionType = ex.GetType() |> string
    exceptionType.Substring(exceptionType.LastIndexOf '.' + 1)

let convertToInt16 (numericStr: string) (provider: IFormatProvider) =
    // Convert numericStr to Int16 without a format provider.
    let defaultValue = 
        try
            Convert.ToInt16 numericStr
            |> string
        with ex ->
            getExceptionType ex

    // Convert numericStr to Int16 with a format provider.
    let providerValue = 
        try
            Convert.ToInt16(numericStr, provider)
            |> string
        with ex ->
            getExceptionType ex

    format numericStr defaultValue providerValue

// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
let provider = NumberFormatInfo()

// These properties affect the conversion.
provider.NegativeSign <- "neg "
provider.PositiveSign <- "pos "

// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator <- "."
provider.NumberGroupSeparator <- ","
provider.NumberGroupSizes <- [| 3 |]
provider.NumberNegativePattern <- 0

printfn
    """This example of
  Convert.ToInt16( string ) and 
  Convert.ToInt16( string, IFormatProvider ) 
generates the following output. It converts several strings to 
short values, using default formatting or a NumberFormatInfo object.
"""
format "String to convert" "Default/exception" "Provider/exception"
format "-----------------" "-----------------" "------------------"

// Convert strings, with and without an IFormatProvider.
convertToInt16 "12345" provider
convertToInt16 "+12345" provider
convertToInt16 "pos 12345" provider
convertToInt16 "-12345" provider
convertToInt16 "neg 12345" provider
convertToInt16 "12345." provider
convertToInt16 "12,345" provider
convertToInt16 "(12345)" provider
convertToInt16 "32768" provider
convertToInt16 "-32769" provider

// This example of
//   Convert.ToInt16( string ) and
//   Convert.ToInt16( string, IFormatProvider )
// generates the following output. It converts several strings to
// short values, using default formatting or a NumberFormatInfo object.
//
// String to convert   Default/exception   Provider/exception
// -----------------   -----------------   ------------------
// 12345               12345               12345
// +12345              12345               FormatException
// pos 12345           FormatException     12345
// -12345              -12345              FormatException
// neg 12345           FormatException     -12345
// 12345.              FormatException     FormatException
// 12,345              FormatException     FormatException
// (12345)             FormatException     FormatException
// 32768               OverflowException   OverflowException
// -32769              OverflowException   FormatException
' Example of the Convert.ToInt16( String ) and 
' Convert.ToInt16( String, IFormatProvider ) methods.
Imports System.Globalization

Module ToInt16ProviderDemo

    Dim format As String = "{0,-20}{1,-20}{2}"

    ' Get the exception type name; remove the namespace prefix.
    Function GetExceptionType( ex As Exception ) As String

        Dim exceptionType   As String = ex.GetType( ).ToString( )
        Return exceptionType.Substring( _
            exceptionType.LastIndexOf( "."c ) + 1 )
    End Function

    Sub ConvertToInt16( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

        ' Convert numericStr to Int16 without a format provider.
        Try
            defaultValue = Convert.ToInt16( numericStr )
        Catch ex As Exception
            defaultValue = GetExceptionType( ex )
        End Try

        ' Convert numericStr to Int16 with a format provider.
        Try
            providerValue = Convert.ToInt16( numericStr, provider )
        Catch ex As Exception
            providerValue = GetExceptionType( ex )
        End Try

        Console.WriteLine( format, numericStr, _
            defaultValue, providerValue )
    End Sub

    Sub Main( )

        ' Create a NumberFormatInfo object and set several of its
        ' properties that apply to numbers.
        Dim provider  As NumberFormatInfo = new NumberFormatInfo( )

        ' These properties affect the conversion.
        provider.NegativeSign = "neg "
        provider.PositiveSign = "pos "

        ' These properties do not affect the conversion.
        ' The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = "."
        provider.NumberGroupSeparator = ","
        provider.NumberGroupSizes = New Integer( ) { 3 }
        provider.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToInt16( String ) and " & vbCrLf & _
            "  Convert.ToInt16( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "Short " & _
            "values, using default formatting " & _
            "or a NumberFormatInfo object." & vbCrLf )
        Console.WriteLine( format, "String to convert", _
            "Default/exception", "Provider/exception" )
        Console.WriteLine( format, "-----------------", _
            "-----------------", "------------------" )

        ' Convert strings, with and without an IFormatProvider.
        ConvertToInt16( "12345", provider )
        ConvertToInt16( "+12345", provider )
        ConvertToInt16( "pos 12345", provider )
        ConvertToInt16( "-12345", provider )
        ConvertToInt16( "neg 12345", provider )
        ConvertToInt16( "12345.", provider )
        ConvertToInt16( "12,345", provider )
        ConvertToInt16( "(12345)", provider )
        ConvertToInt16( "32768", provider )
        ConvertToInt16( "-32769", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToInt16( String ) and
'   Convert.ToInt16( String, IFormatProvider )
' generates the following output. It converts several strings to
' Short values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 12345               12345               12345
' +12345              12345               FormatException
' pos 12345           FormatException     12345
' -12345              -12345              FormatException
' neg 12345           FormatException     -12345
' 12345.              FormatException     FormatException
' 12,345              FormatException     FormatException
' (12345)             FormatException     FormatException
' 32768               OverflowException   OverflowException
' -32769              OverflowException   FormatException

注解

provider是获取IFormatProviderNumberFormatInfo对象的实例。 该 NumberFormatInfo 对象提供有关格式的 value区域性特定信息。 null如果是providerNumberFormatInfo则使用当前区域性。

如果不希望在转换失败时处理异常,可以改为调用该方法 Int16.TryParse 。 它返回一个 Boolean 值,该值指示转换是成功还是失败。

另请参阅

适用于

ToInt16(Object, IFormatProvider)

使用指定的区域性特定格式信息,将指定对象的值转换为 16 位带符号整数。

public:
 static short ToInt16(System::Object ^ value, IFormatProvider ^ provider);
public static short ToInt16 (object value, IFormatProvider provider);
public static short ToInt16 (object? value, IFormatProvider? provider);
static member ToInt16 : obj * IFormatProvider -> int16
Public Shared Function ToInt16 (value As Object, provider As IFormatProvider) As Short

参数

value
Object

一个实现 IConvertible 接口的对象。

provider
IFormatProvider

一个提供区域性特定的格式设置信息的对象。

返回

Int16

一个与 value 等效的 16 位带符号整数,如果 valuenull,则为零。

例外

对于 Int16 类型,value 的格式不正确。

value 不实现 IConvertible

示例

以下示例定义一个实现 IConvertible 的类和实现的 IFormatProvider类。 实现的 IConvertible 类的对象包含值数组 Double 。 每个类的对象将 ToInt16 传递给方法。 此方法使用实现IFormatProvider以确定如何计算平均值的对象返回值的数组Double的平均值。

using namespace System;
using namespace System::Collections;

// Define the types of averaging available in the class 
// implementing IConvertible.
public enum class AverageType : short
{
   None = 0,
   GeometricMean = 1,
   ArithmeticMean = 2,
   Median = 3
};


// Pass an instance of this class to methods that require an 
// IFormatProvider. The class instance determines the type of 
// average to calculate.
ref class AverageInfo: public IFormatProvider
{
protected:
   AverageType AvgType;

public:

   // Specify the type of averaging in the constructor.
   AverageInfo( AverageType avgType )
   {
      this->AvgType = avgType;
   }


   // This method returns a reference to the containing object 
   // if an object of AverageInfo type is requested. 
   virtual Object^ GetFormat( Type^ argType )
   {
      if ( argType == AverageInfo::typeid)
            return this;
      else
            return (Object^)0;
   }


   property AverageType TypeOfAverage 
   {

      // Use this property to set or get the type of averaging.
      AverageType get()
      {
         return this->AvgType;
      }

      void set( AverageType value )
      {
         this->AvgType = value;
      }

   }

};


// This class encapsulates an array of double values and implements 
// the IConvertible interface. Most of the IConvertible methods 
// return an average of the array elements in one of three types: 
// arithmetic mean, geometric mean, or median. 
ref class DataSet: public IConvertible
{
private:
   static Object^ null = nullptr;

protected:
   ArrayList^ data;
   AverageInfo^ defaultProvider;

   // This method unboxes a boxed double.
   double UnBoxDouble( Object^ obj )
   {
      return  *static_cast<double^>(obj);
   }


public:

   // Construct the object and add an initial list of values.
   // Create a default format provider.
   DataSet( ... array<Double>^values )
   {
      data = gcnew ArrayList( (Array^)values );
      defaultProvider = gcnew AverageInfo( AverageType::ArithmeticMean );
   }


   // Add additional values with this method.
   int Add( double value )
   {
      data->Add( value );
      return data->Count;
   }


   property double Item[ int ]
   {

      // Get, set, and add values with this indexer property.
      double get( int index )
      {
         if ( index >= 0 && index < data->Count )
                  return UnBoxDouble( data[ index ] );
         else
                  throw gcnew InvalidOperationException( "[DataSet.get] Index out of range." );
      }

      void set( int index, double value )
      {
         if ( index >= 0 && index < data->Count )
                  data[ index ] = value;
         else
         if ( index == data->Count )
                  data->Add( value );
         else
                  throw gcnew InvalidOperationException( "[DataSet.set] Index out of range." );
      }

   }

   property int Count 
   {

      // This property returns the number of elements in the object.
      int get()
      {
         return data->Count;
      }

   }

protected:

   // This method calculates the average of the object's elements.
   double Average( AverageType avgType )
   {
      double SumProd;
      if ( data->Count == 0 )
            return 0.0;

      switch ( avgType )
      {
         case AverageType::GeometricMean:
            SumProd = 1.0;
            for ( int Index = 0; Index < data->Count; Index++ )
               SumProd *= UnBoxDouble( data[ Index ] );
            
            // This calculation will not fail with negative 
            // elements.
            return Math::Sign( SumProd ) * Math::Pow( Math::Abs( SumProd ), 1.0 / data->Count );

         case AverageType::ArithmeticMean:
            SumProd = 0.0;
            for ( int Index = 0; Index < data->Count; Index++ )
               SumProd += UnBoxDouble( data[ Index ] );
            return SumProd / data->Count;

         case AverageType::Median:
            if ( data->Count % 2 == 0 )
                        return (UnBoxDouble( data[ data->Count / 2 ] ) + UnBoxDouble( data[ data->Count / 2 - 1 ] )) / 2.0;
            else
                        return UnBoxDouble( data[ data->Count / 2 ] );

         default:
            return 0.0;
      }
   }


   // Get the AverageInfo object from the caller's format provider,
   // or use the local default.
   AverageInfo^ GetAverageInfo( IFormatProvider^ provider )
   {
      AverageInfo^ avgInfo = nullptr;
      if ( provider != nullptr )
            avgInfo = static_cast<AverageInfo^>(provider->GetFormat( AverageInfo::typeid ));

      if ( avgInfo == nullptr )
            return defaultProvider;
      else
            return avgInfo;
   }


   // Calculate the average and limit the range.
   double CalcNLimitAverage( double min, double max, IFormatProvider^ provider )
   {
      
      // Get the format provider and calculate the average.
      AverageInfo^ avgInfo = GetAverageInfo( provider );
      double avg = Average( avgInfo->TypeOfAverage );
      
      // Limit the range, based on the minimum and maximum values 
      // for the type.
      return avg > max ? max : avg < min ? min : avg;
   }


public:

   // The following elements are required by IConvertible.
   // None of these conversion functions throw exceptions. When
   // the data is out of range for the type, the appropriate
   // MinValue or MaxValue is used.
   virtual TypeCode GetTypeCode()
   {
      return TypeCode::Object;
   }

   virtual bool ToBoolean( IFormatProvider^ provider )
   {
      
      // ToBoolean is false if the dataset is empty.
      if ( data->Count <= 0 )
            return false;
      // For median averaging, ToBoolean is true if any 
      // non-discarded elements are nonzero.
      else
      
      // For median averaging, ToBoolean is true if any 
      // non-discarded elements are nonzero.
      if ( AverageType::Median == GetAverageInfo( provider )->TypeOfAverage )
      {
         if ( data->Count % 2 == 0 )
                  return (UnBoxDouble( data[ data->Count / 2 ] ) != 0.0 || UnBoxDouble( data[ data->Count / 2 - 1 ] ) != 0.0);
         else
                  return UnBoxDouble( data[ data->Count / 2 ] ) != 0.0;
      }
      // For arithmetic or geometric mean averaging, ToBoolean is 
      // true if any element of the dataset is nonzero.  
      else
      {
         for ( int Index = 0; Index < data->Count; Index++ )
            if ( UnBoxDouble( data[ Index ] ) != 0.0 )
                        return true;
         return false;
      }
   }

   virtual Byte ToByte( IFormatProvider^ provider )
   {
      return Convert::ToByte( CalcNLimitAverage( Byte::MinValue, Byte::MaxValue, provider ) );
   }

   virtual Char ToChar( IFormatProvider^ provider )
   {
      return Convert::ToChar( Convert::ToUInt16( CalcNLimitAverage( Char::MinValue, Char::MaxValue, provider ) ) );
   }


   // Convert to DateTime by adding the calculated average as 
   // seconds to the current date and time. A valid DateTime is 
   // always returned.
   virtual DateTime ToDateTime( IFormatProvider^ provider )
   {
      double seconds = Average( GetAverageInfo( provider )->TypeOfAverage );
      try
      {
         return DateTime::Now.AddSeconds( seconds );
      }
      catch ( ArgumentOutOfRangeException^ ) 
      {
         return seconds < 0.0 ? DateTime::MinValue : DateTime::MaxValue;
      }

   }

   virtual Decimal ToDecimal( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds Decimal.MinValue and 
      // Decimal.MaxValue to invalid Decimal values, so the 
      // following limits must be used.
      return Convert::ToDecimal( CalcNLimitAverage(  -79228162514264330000000000000.0, 79228162514264330000000000000.0, provider ) );
   }

   virtual double ToDouble( IFormatProvider^ provider )
   {
      return Average( GetAverageInfo( provider )->TypeOfAverage );
   }

   virtual short ToInt16( IFormatProvider^ provider )
   {
      return Convert::ToInt16( CalcNLimitAverage( Int16::MinValue, Int16::MaxValue, provider ) );
   }

   virtual int ToInt32( IFormatProvider^ provider )
   {
      return Convert::ToInt32( CalcNLimitAverage( Int32::MinValue, Int32::MaxValue, provider ) );
   }

   virtual __int64 ToInt64( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds Int64.MinValue and 
      // Int64.MaxValue to invalid Int64 values, so the following 
      // limits must be used.
      return Convert::ToInt64( CalcNLimitAverage(  -9223372036854775000, 9223372036854775000, provider ) );
   }

   virtual signed char ToSByte( IFormatProvider^ provider )
   {
      return Convert::ToSByte( CalcNLimitAverage( SByte::MinValue, SByte::MaxValue, provider ) );
   }

   virtual float ToSingle( IFormatProvider^ provider )
   {
      return Convert::ToSingle( CalcNLimitAverage( Single::MinValue, Single::MaxValue, provider ) );
   }

   virtual UInt16 ToUInt16( IFormatProvider^ provider )
   {
      return Convert::ToUInt16( CalcNLimitAverage( UInt16::MinValue, UInt16::MaxValue, provider ) );
   }

   virtual UInt32 ToUInt32( IFormatProvider^ provider )
   {
      return Convert::ToUInt32( CalcNLimitAverage( UInt32::MinValue, UInt32::MaxValue, provider ) );
   }

   virtual UInt64 ToUInt64( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds UInt64.MaxValue to an invalid
      // UInt64 value, so the following limit must be used.
      return Convert::ToUInt64( CalcNLimitAverage( 0, 18446744073709550000.0, provider ) );
   }

   virtual Object^ ToType( Type^ conversionType, IFormatProvider^ provider )
   {
      return Convert::ChangeType( Average( GetAverageInfo( provider )->TypeOfAverage ), conversionType );
   }

   virtual String^ ToString( IFormatProvider^ provider )
   {
      AverageType avgType = GetAverageInfo( provider )->TypeOfAverage;
      return String::Format( "( {0}: {1:G10} )", avgType, Average( avgType ) );
   }

};


// Display a DataSet with three different format providers.
void DisplayDataSet( DataSet^ ds )
{
   IFormatProvider^ null = nullptr;
   String^ fmt = "{0,-12}{1,20}{2,20}{3,20}";
   AverageInfo^ median = gcnew AverageInfo( AverageType::Median );
   AverageInfo^ geMean = gcnew AverageInfo( AverageType::GeometricMean );
   
   // Display the dataset elements.
   if ( ds->Count > 0 )
   {
      Console::Write( "\nDataSet: [{0}", ds->Item[ 0 ] );
      for ( int iX = 1; iX < ds->Count; iX++ )
         Console::Write( ", {0}", ds->Item[ iX ] );
      Console::WriteLine( "]\n" );
   }

   Console::WriteLine( fmt, "Convert::", "Default", "Geometric Mean", "Median" );
   Console::WriteLine( fmt, "---------", "-------", "--------------", "------" );
   Console::WriteLine( fmt, "ToBoolean", Convert::ToBoolean( ds, null ), Convert::ToBoolean( ds, geMean ), Convert::ToBoolean( ds, median ) );
   Console::WriteLine( fmt, "ToByte", Convert::ToByte( ds, null ), Convert::ToByte( ds, geMean ), Convert::ToByte( ds, median ) );
   Console::WriteLine( fmt, "ToChar", Convert::ToChar( ds, null ), Convert::ToChar( ds, geMean ), Convert::ToChar( ds, median ) );
   Console::WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}"
   "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", "ToDateTime", Convert::ToDateTime( ds, null ), Convert::ToDateTime( ds, geMean ), Convert::ToDateTime( ds, median ) );
   Console::WriteLine( fmt, "ToDecimal", Convert::ToDecimal( ds, null ), Convert::ToDecimal( ds, geMean ), Convert::ToDecimal( ds, median ) );
   Console::WriteLine( fmt, "ToDouble", Convert::ToDouble( ds, null ), Convert::ToDouble( ds, geMean ), Convert::ToDouble( ds, median ) );
   Console::WriteLine( fmt, "ToInt16", Convert::ToInt16( ds, null ), Convert::ToInt16( ds, geMean ), Convert::ToInt16( ds, median ) );
   Console::WriteLine( fmt, "ToInt32", Convert::ToInt32( ds, null ), Convert::ToInt32( ds, geMean ), Convert::ToInt32( ds, median ) );
   Console::WriteLine( fmt, "ToInt64", Convert::ToInt64( ds, null ), Convert::ToInt64( ds, geMean ), Convert::ToInt64( ds, median ) );
   Console::WriteLine( fmt, "ToSByte", Convert::ToSByte( ds, null ), Convert::ToSByte( ds, geMean ), Convert::ToSByte( ds, median ) );
   Console::WriteLine( fmt, "ToSingle", Convert::ToSingle( ds, null ), Convert::ToSingle( ds, geMean ), Convert::ToSingle( ds, median ) );
   Console::WriteLine( fmt, "ToUInt16", Convert::ToUInt16( ds, null ), Convert::ToUInt16( ds, geMean ), Convert::ToUInt16( ds, median ) );
   Console::WriteLine( fmt, "ToUInt32", Convert::ToUInt32( ds, null ), Convert::ToUInt32( ds, geMean ), Convert::ToUInt32( ds, median ) );
   Console::WriteLine( fmt, "ToUInt64", Convert::ToUInt64( ds, null ), Convert::ToUInt64( ds, geMean ), Convert::ToUInt64( ds, median ) );
}

int main()
{
   Console::WriteLine( "This example of the "
   "Convert::To<Type>( Object*, IFormatProvider* ) methods "
   "\ngenerates the following output. The example "
   "displays the values \nreturned by the methods, "
   "using several IFormatProvider objects.\n" );
   
   // To call a [ParamArray] method in C++, you cannot just
   // list the parameters, you need to build an array.
   array<Double>^dataElem = gcnew array<Double>(6);
   dataElem[ 0 ] = 10.5;
   dataElem[ 1 ] = 22.2;
   dataElem[ 2 ] = 45.9;
   dataElem[ 3 ] = 88.7;
   dataElem[ 4 ] = 156.05;
   dataElem[ 5 ] = 297.6;
   DataSet^ ds1 = gcnew DataSet( dataElem );
   DisplayDataSet( ds1 );
   dataElem = gcnew array<Double>(5);
   dataElem[ 0 ] = 359999.95;
   dataElem[ 1 ] = 425000;
   dataElem[ 2 ] = 499999.5;
   dataElem[ 3 ] = 775000;
   dataElem[ 4 ] = 1695000;
   DataSet^ ds2 = gcnew DataSet( dataElem );
   DisplayDataSet( ds2 );
}

/*
This example of the Convert::To<Type>( Object*, IFormatProvider* ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.

DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]

Convert::                Default      Geometric Mean              Median
---------                -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       103                  59                  67
ToChar                         g                   ;                   C
ToDateTime   2003-05-13 15:30:23 2003-05-13 15:29:39 2003-05-13 15:29:47
ToDecimal       103.491666666667    59.4332135445164                67.3
ToDouble        103.491666666667    59.4332135445164                67.3
ToInt16                      103                  59                  67
ToInt32                      103                  59                  67
ToInt64                      103                  59                  67
ToSByte                      103                  59                  67
ToSingle                103.4917            59.43321                67.3
ToUInt16                     103                  59                  67
ToUInt32                     103                  59                  67
ToUInt64                     103                  59                  67

DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]

Convert::                Default      Geometric Mean              Median
---------                -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       255                 255                 255
ToChar                         ?                   ?                   ?
ToDateTime   2003-05-22 08:05:19 2003-05-20 22:54:57 2003-05-19 10:21:59
ToDecimal              750999.89    631577.237188435            499999.5
ToDouble               750999.89    631577.237188435            499999.5
ToInt16                    32767               32767               32767
ToInt32                   751000              631577              500000
ToInt64                   751000              631577              500000
ToSByte                      127                 127                 127
ToSingle                750999.9            631577.3            499999.5
ToUInt16                   65535               65535               65535
ToUInt32                  751000              631577              500000
ToUInt64                  751000              631577              500000
*/
using System;
using System.Collections;

// Define the types of averaging available in the class
// implementing IConvertible.
public enum AverageType : short
{
    None = 0,
    GeometricMean = 1,
    ArithmeticMean = 2,
    Median = 3
};

// Pass an instance of this class to methods that require an
// IFormatProvider. The class instance determines the type of
// average to calculate.
public class AverageInfo : IFormatProvider
{
    protected AverageType AvgType;

    // Specify the type of averaging in the constructor.
    public AverageInfo( AverageType avgType )
    {
        this.AvgType = avgType;
    }

    // This method returns a reference to the containing object
    // if an object of AverageInfo type is requested.
    public object GetFormat( Type argType )
    {
        if ( argType == typeof( AverageInfo ) )
            return this;
        else
            return null;
    }

    // Use this property to set or get the type of averaging.
    public AverageType TypeOfAverage
    {
        get { return this.AvgType; }
        set { this.AvgType = value; }
    }
}

// This class encapsulates an array of double values and implements
// the IConvertible interface. Most of the IConvertible methods
// return an average of the array elements in one of three types:
// arithmetic mean, geometric mean, or median.
public class DataSet : IConvertible
{
    protected ArrayList     data;
    protected AverageInfo   defaultProvider;

    // Construct the object and add an initial list of values.
    // Create a default format provider.
    public DataSet( params double[ ] values )
    {
        data = new ArrayList( values );
        defaultProvider =
            new AverageInfo( AverageType.ArithmeticMean );
    }

    // Add additional values with this method.
    public int Add( double value )
    {
        data.Add( value );
        return data.Count;
    }

    // Get, set, and add values with this indexer property.
    public double this[ int index ]
    {
        get
        {
            if( index >= 0 && index < data.Count )
                return (double)data[ index ];
            else
                throw new InvalidOperationException(
                    "[DataSet.get] Index out of range." );
        }
        set
        {
            if( index >= 0 && index < data.Count )
                data[ index ] = value;

            else if( index == data.Count )
                data.Add( value );
            else
                throw new InvalidOperationException(
                    "[DataSet.set] Index out of range." );
        }
    }

    // This property returns the number of elements in the object.
    public int Count
    {
        get { return data.Count; }
    }

    // This method calculates the average of the object's elements.
    protected double Average( AverageType avgType )
    {
        double  SumProd;

        if( data.Count == 0 )
            return 0.0;

        switch( avgType )
        {
            case AverageType.GeometricMean:

                SumProd = 1.0;
                for( int Index = 0; Index < data.Count; Index++ )
                    SumProd *= (double)data[ Index ];

                // This calculation will not fail with negative
                // elements.
                return Math.Sign( SumProd ) * Math.Pow(
                    Math.Abs( SumProd ), 1.0 / data.Count );

            case AverageType.ArithmeticMean:

                SumProd = 0.0;
                for( int Index = 0; Index < data.Count; Index++ )
                    SumProd += (double)data[ Index ];

                return SumProd / data.Count;

            case AverageType.Median:

                if( data.Count % 2 == 0 )
                    return ( (double)data[ data.Count / 2 ] +
                        (double)data[ data.Count / 2 - 1 ] ) / 2.0;
                else
                    return (double)data[ data.Count / 2 ];

            default:
                return 0.0;
        }
    }

    // Get the AverageInfo object from the caller's format provider,
    // or use the local default.
    protected AverageInfo GetAverageInfo( IFormatProvider provider )
    {
        AverageInfo avgInfo = null;

        if( provider != null )
            avgInfo = (AverageInfo)provider.GetFormat(
                typeof( AverageInfo ) );

        if ( avgInfo == null )
            return defaultProvider;
        else
            return avgInfo;
    }

    // Calculate the average and limit the range.
    protected double CalcNLimitAverage( double min, double max,
        IFormatProvider provider )
    {
        // Get the format provider and calculate the average.
        AverageInfo avgInfo = GetAverageInfo( provider );
        double avg = Average( avgInfo.TypeOfAverage );

        // Limit the range, based on the minimum and maximum values
        // for the type.
        return avg > max ? max : avg < min ? min : avg;
    }

    // The following elements are required by IConvertible.

    // None of these conversion functions throw exceptions. When
    // the data is out of range for the type, the appropriate
    // MinValue or MaxValue is used.
    public TypeCode GetTypeCode( )
    {
        return TypeCode.Object;
    }

    public bool ToBoolean( IFormatProvider provider )
    {
        // ToBoolean is false if the dataset is empty.
        if( data.Count <= 0 )
        {
            return false;
        }

        // For median averaging, ToBoolean is true if any
        // non-discarded elements are nonzero.
        else if( AverageType.Median ==
            GetAverageInfo( provider ).TypeOfAverage )
        {
            if (data.Count % 2 == 0 )
                return ( (double)data[ data.Count / 2 ] != 0.0 ||
                    (double)data[ data.Count / 2 - 1 ] != 0.0 );
            else
                return (double)data[ data.Count / 2 ] != 0.0;
        }

        // For arithmetic or geometric mean averaging, ToBoolean is
        // true if any element of the dataset is nonzero.
        else
        {
            for( int Index = 0; Index < data.Count; Index++ )
                if( (double)data[ Index ] != 0.0 )
                    return true;
            return false;
        }
    }

    public byte ToByte( IFormatProvider provider )
    {
        return Convert.ToByte( CalcNLimitAverage(
            Byte.MinValue, Byte.MaxValue, provider ) );
    }

    public char ToChar( IFormatProvider provider )
    {
        return Convert.ToChar( Convert.ToUInt16( CalcNLimitAverage(
            Char.MinValue, Char.MaxValue, provider ) ) );
    }

    // Convert to DateTime by adding the calculated average as
    // seconds to the current date and time. A valid DateTime is
    // always returned.
    public DateTime ToDateTime( IFormatProvider provider )
    {
        double seconds =
            Average( GetAverageInfo( provider ).TypeOfAverage );
        try
        {
            return DateTime.Now.AddSeconds( seconds );
        }
        catch( ArgumentOutOfRangeException )
        {
            return seconds < 0.0 ? DateTime.MinValue : DateTime.MaxValue;
        }
    }

    public decimal ToDecimal( IFormatProvider provider )
    {
        // The Double conversion rounds Decimal.MinValue and
        // Decimal.MaxValue to invalid Decimal values, so the
        // following limits must be used.
        return Convert.ToDecimal( CalcNLimitAverage(
            -79228162514264330000000000000.0,
            79228162514264330000000000000.0, provider ) );
    }

    public double ToDouble( IFormatProvider provider )
    {
        return Average( GetAverageInfo(provider).TypeOfAverage );
    }

    public short ToInt16( IFormatProvider provider )
    {
        return Convert.ToInt16( CalcNLimitAverage(
            Int16.MinValue, Int16.MaxValue, provider ) );
    }

    public int ToInt32( IFormatProvider provider )
    {
        return Convert.ToInt32( CalcNLimitAverage(
            Int32.MinValue, Int32.MaxValue, provider ) );
    }

    public long ToInt64( IFormatProvider provider )
    {
        // The Double conversion rounds Int64.MinValue and
        // Int64.MaxValue to invalid Int64 values, so the following
        // limits must be used.
        return Convert.ToInt64( CalcNLimitAverage(
            -9223372036854775000, 9223372036854775000, provider ) );
    }

    public SByte ToSByte( IFormatProvider provider )
    {
        return Convert.ToSByte( CalcNLimitAverage(
            SByte.MinValue, SByte.MaxValue, provider ) );
    }

    public float ToSingle( IFormatProvider provider )
    {
        return Convert.ToSingle( CalcNLimitAverage(
            Single.MinValue, Single.MaxValue, provider ) );
    }

    public UInt16 ToUInt16( IFormatProvider provider )
    {
        return Convert.ToUInt16( CalcNLimitAverage(
            UInt16.MinValue, UInt16.MaxValue, provider ) );
    }

    public UInt32 ToUInt32( IFormatProvider provider )
    {
        return Convert.ToUInt32( CalcNLimitAverage(
            UInt32.MinValue, UInt32.MaxValue, provider ) );
    }

    public UInt64 ToUInt64( IFormatProvider provider )
    {
        // The Double conversion rounds UInt64.MaxValue to an invalid
        // UInt64 value, so the following limit must be used.
        return Convert.ToUInt64( CalcNLimitAverage(
            0, 18446744073709550000.0, provider ) );
    }

    public object ToType( Type conversionType,
        IFormatProvider provider )
    {
        return Convert.ChangeType( Average(
            GetAverageInfo( provider ).TypeOfAverage ),
            conversionType );
    }

    public string ToString( IFormatProvider provider )
    {
        AverageType avgType = GetAverageInfo( provider ).TypeOfAverage;
        return String.Format( "( {0}: {1:G10} )", avgType,
            Average( avgType ) );
    }
}

class IConvertibleProviderDemo
{
    // Display a DataSet with three different format providers.
    public static void DisplayDataSet( DataSet ds )
    {
        string      fmt    = "{0,-12}{1,20}{2,20}{3,20}";
        AverageInfo median = new AverageInfo( AverageType.Median );
        AverageInfo geMean =
            new AverageInfo( AverageType.GeometricMean );

         // Display the dataset elements.
        if( ds.Count > 0 )
        {
            Console.Write( "\nDataSet: [{0}", ds[ 0 ] );
            for( int iX = 1; iX < ds.Count; iX++ )
                Console.Write( ", {0}", ds[ iX ] );
            Console.WriteLine( "]\n" );
        }

        Console.WriteLine( fmt, "Convert.", "Default",
            "Geometric Mean", "Median");
        Console.WriteLine( fmt, "--------", "-------",
            "--------------", "------");
        Console.WriteLine( fmt, "ToBoolean",
            Convert.ToBoolean( ds, null ),
            Convert.ToBoolean( ds, geMean ),
            Convert.ToBoolean( ds, median ) );
        Console.WriteLine( fmt, "ToByte",
            Convert.ToByte( ds, null ),
            Convert.ToByte( ds, geMean ),
            Convert.ToByte( ds, median ) );
        Console.WriteLine( fmt, "ToChar",
            Convert.ToChar( ds, null ),
            Convert.ToChar( ds, geMean ),
            Convert.ToChar( ds, median ) );
        Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" +
            "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}",
            "ToDateTime", Convert.ToDateTime( ds, null ),
            Convert.ToDateTime( ds, geMean ),
            Convert.ToDateTime( ds, median ) );
        Console.WriteLine( fmt, "ToDecimal",
            Convert.ToDecimal( ds, null ),
            Convert.ToDecimal( ds, geMean ),
            Convert.ToDecimal( ds, median ) );
        Console.WriteLine( fmt, "ToDouble",
            Convert.ToDouble( ds, null ),
            Convert.ToDouble( ds, geMean ),
            Convert.ToDouble( ds, median ) );
        Console.WriteLine( fmt, "ToInt16",
            Convert.ToInt16( ds, null ),
            Convert.ToInt16( ds, geMean ),
            Convert.ToInt16( ds, median ) );
        Console.WriteLine( fmt, "ToInt32",
            Convert.ToInt32( ds, null ),
            Convert.ToInt32( ds, geMean ),
            Convert.ToInt32( ds, median ) );
        Console.WriteLine( fmt, "ToInt64",
            Convert.ToInt64( ds, null ),
            Convert.ToInt64( ds, geMean ),
            Convert.ToInt64( ds, median ) );
        Console.WriteLine( fmt, "ToSByte",
            Convert.ToSByte( ds, null ),
            Convert.ToSByte( ds, geMean ),
            Convert.ToSByte( ds, median ) );
        Console.WriteLine( fmt, "ToSingle",
            Convert.ToSingle( ds, null ),
            Convert.ToSingle( ds, geMean ),
            Convert.ToSingle( ds, median ) );
        Console.WriteLine( fmt, "ToUInt16",
            Convert.ToUInt16( ds, null ),
            Convert.ToUInt16( ds, geMean ),
            Convert.ToUInt16( ds, median ) );
        Console.WriteLine( fmt, "ToUInt32",
            Convert.ToUInt32( ds, null ),
            Convert.ToUInt32( ds, geMean ),
            Convert.ToUInt32( ds, median ) );
        Console.WriteLine( fmt, "ToUInt64",
            Convert.ToUInt64( ds, null ),
            Convert.ToUInt64( ds, geMean ),
            Convert.ToUInt64( ds, median ) );
    }

    public static void Main( )
    {
        Console.WriteLine( "This example of " +
            "the Convert.To<Type>( object, IFormatProvider ) methods " +
            "\ngenerates the following output. The example " +
            "displays the values \nreturned by the methods, " +
            "using several IFormatProvider objects.\n" );

        DataSet ds1 = new DataSet(
            10.5, 22.2, 45.9, 88.7, 156.05, 297.6 );
        DisplayDataSet( ds1 );

        DataSet ds2 = new DataSet(
            359999.95, 425000, 499999.5, 775000, 1695000 );
        DisplayDataSet( ds2 );
    }
}

/*
This example of the Convert.To<Type>( object, IFormatProvider ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.

DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]

Convert.                 Default      Geometric Mean              Median
--------                 -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       103                  59                  67
ToChar                         g                   ;                   C
ToDateTime   2003-05-13 15:04:12 2003-05-13 15:03:28 2003-05-13 15:03:35
ToDecimal       103.491666666667    59.4332135445164                67.3
ToDouble        103.491666666667    59.4332135445164                67.3
ToInt16                      103                  59                  67
ToInt32                      103                  59                  67
ToInt64                      103                  59                  67
ToSByte                      103                  59                  67
ToSingle                103.4917            59.43321                67.3
ToUInt16                     103                  59                  67
ToUInt32                     103                  59                  67
ToUInt64                     103                  59                  67

DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]

Convert.                 Default      Geometric Mean              Median
--------                 -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       255                 255                 255
ToChar                         ?                   ?                   ?
ToDateTime   2003-05-22 07:39:08 2003-05-20 22:28:45 2003-05-19 09:55:48
ToDecimal              750999.89    631577.237188435            499999.5
ToDouble               750999.89    631577.237188435            499999.5
ToInt16                    32767               32767               32767
ToInt32                   751000              631577              500000
ToInt64                   751000              631577              500000
ToSByte                      127                 127                 127
ToSingle                750999.9            631577.3            499999.5
ToUInt16                   65535               65535               65535
ToUInt32                  751000              631577              500000
ToUInt64                  751000              631577              500000
*/
open System
open System.Collections

// Define the types of averaging available in the class
// implementing IConvertible.
type AverageType =
    | None = 0s
    | GeometricMean = 1s
    | ArithmeticMean = 2s
    | Median = 3s

// Pass an instance of this class to methods that require an
// IFormatProvider. The class instance determines the type of
// average to calculate.
[<AllowNullLiteral>]
type AverageInfo(avgType: AverageType) =
    // Use this property to set or get the type of averaging.
    member val TypeOfAverage = avgType with get, set 
    
    interface IFormatProvider with
        // This method returns a reference to the containing object
        // if an object of AverageInfo type is requested.
        member this.GetFormat(argType: Type) =
            if argType = typeof<AverageInfo> then
                this
            else
                null

// This class encapsulates an array of double values and implements
// the IConvertible interface. Most of the IConvertible methods
// an average of the array elements in one of three types:
// arithmetic mean, geometric mean, or median.
type DataSet([<ParamArray>] values: double[]) =
    let data = ResizeArray values
    let defaultProvider =
        AverageInfo AverageType.ArithmeticMean

    // Add additional values with this method.
    member _.Add(value: double) =
        data.Add value
        data.Count

    // Get, set, and add values with this indexer property.
    member _.Item
        with get (index) =
            if index >= 0 && index < data.Count then
                data[index]
            else
                raise (InvalidOperationException "[DataSet.get] Index out of range.")
        and set index value =
            if index >= 0 && index < data.Count then
                data[index] <- value
            elif index = data.Count then
                data.Add value
            else
                raise (InvalidOperationException "[DataSet.set] Index out of range.")

    // This property returns the number of elements in the object.
    member _.Count =
        data.Count

    // This method calculates the average of the object's elements.
    member _.Average(avgType: AverageType) =
        if data.Count = 0 then
            0.0
        else
            match avgType with
            | AverageType.GeometricMean ->
                let sumProd =
                    Seq.reduce ( * ) data
                
                // This calculation will not fail with negative
                // elements.
                (sign sumProd |> float) * Math.Pow(abs sumProd, 1.0 / (float data.Count))

            | AverageType.ArithmeticMean ->
                Seq.average data

            | AverageType.Median ->
                if data.Count % 2 = 0 then
                    (data[data.Count / 2] + data[data.Count / 2 - 1]) / 2.0
                else
                    data[ data.Count / 2]
            | _ ->
                0.0

    // Get the AverageInfo object from the caller's format provider,
    // or use the local default.
    member _.GetAverageInfo(provider: IFormatProvider) =
        let avgInfo =
            if provider <> null then
                provider.GetFormat typeof<AverageInfo> :?> AverageInfo
            else 
                null

        if avgInfo = null then
            defaultProvider
        else
            avgInfo

    // Calculate the average and limit the range.
    member this.CalcNLimitAverage(min: double, max: double, provider: IFormatProvider) =
        // Get the format provider and calculate the average.
        let avgInfo = this.GetAverageInfo provider
        let avg = this.Average avgInfo.TypeOfAverage

        // Limit the range, based on the minimum and maximum values
        // for the type.
        if avg > max then max elif avg < min then min else avg

    // The following elements are required by IConvertible.
    interface IConvertible with
        // None of these conversion functions throw exceptions. When
        // the data is out of range for the type, the appropriate
        // MinValue or MaxValue is used.
        member _.GetTypeCode() =
            TypeCode.Object

        member this.ToBoolean(provider: IFormatProvider) =
            // ToBoolean is false if the dataset is empty.
            if data.Count <= 0 then
                false

            // For median averaging, ToBoolean is true if any
            // non-discarded elements are nonzero.
            elif AverageType.Median = this.GetAverageInfo(provider).TypeOfAverage then
                if data.Count % 2 = 0 then
                    (data[data.Count / 2] <> 0.0 || data[data.Count / 2 - 1] <> 0.0)
                else
                    data[data.Count / 2] <> 0.0

            // For arithmetic or geometric mean averaging, ToBoolean is
            // true if any element of the dataset is nonzero.
            else
                Seq.exists (fun x -> x <> 0.0) data

        member this.ToByte(provider: IFormatProvider) =
            Convert.ToByte(this.CalcNLimitAverage(float Byte.MinValue, float Byte.MaxValue, provider) )

        member this.ToChar(provider: IFormatProvider) =
            Convert.ToChar(Convert.ToUInt16(this.CalcNLimitAverage(float Char.MinValue, float Char.MaxValue, provider) ) )

        // Convert to DateTime by adding the calculated average as
        // seconds to the current date and time. A valid DateTime is
        // always returned.
        member this.ToDateTime(provider: IFormatProvider) =
            let seconds = this.Average(this.GetAverageInfo(provider).TypeOfAverage)
            try
                DateTime.Now.AddSeconds seconds
            with :? ArgumentOutOfRangeException ->
                if seconds < 0.0 then DateTime.MinValue else DateTime.MaxValue

        member this.ToDecimal(provider: IFormatProvider) =
            // The Double conversion rounds Decimal.MinValue and
            // Decimal.MaxValue to invalid Decimal values, so the
            // following limits must be used.
            Convert.ToDecimal(this.CalcNLimitAverage(-79228162514264330000000000000.0, 79228162514264330000000000000.0, provider) )

        member this.ToDouble(provider: IFormatProvider) =
            this.Average(this.GetAverageInfo(provider).TypeOfAverage)

        member this.ToInt16(provider: IFormatProvider) =
            Convert.ToInt16(this.CalcNLimitAverage(float Int16.MinValue, float Int16.MaxValue, provider) )

        member this.ToInt32(provider: IFormatProvider) =
            Convert.ToInt32(this.CalcNLimitAverage(Int32.MinValue, Int32.MaxValue, provider) )

        member this.ToInt64(provider: IFormatProvider) =
            // The Double conversion rounds Int64.MinValue and
            // Int64.MaxValue to invalid Int64 values, so the following
            // limits must be used.
            Convert.ToInt64(this.CalcNLimitAverage(-9223372036854775000., 9223372036854775000., provider) )

        member this.ToSByte(provider: IFormatProvider) =
            Convert.ToSByte(this.CalcNLimitAverage(float SByte.MinValue, float SByte.MaxValue, provider) )

        member this.ToSingle(provider: IFormatProvider) =
            Convert.ToSingle(this.CalcNLimitAverage(float Single.MinValue, float Single.MaxValue, provider) )

        member this.ToUInt16(provider: IFormatProvider) =
            Convert.ToUInt16(this.CalcNLimitAverage(float UInt16.MinValue, float UInt16.MaxValue, provider) )

        member this.ToUInt32(provider: IFormatProvider) =
            Convert.ToUInt32(this.CalcNLimitAverage(float UInt32.MinValue, float UInt32.MaxValue, provider) )

        member this.ToUInt64(provider: IFormatProvider) =
            // The Double conversion rounds UInt64.MaxValue to an invalid
            // UInt64 value, so the following limit must be used.
            Convert.ToUInt64(this.CalcNLimitAverage(0, 18446744073709550000.0, provider) )

        member this.ToType(conversionType: Type, provider: IFormatProvider) =
            Convert.ChangeType(this.Average(this.GetAverageInfo(provider).TypeOfAverage), conversionType)

        member this.ToString(provider: IFormatProvider) =
            let avgType = this.GetAverageInfo(provider).TypeOfAverage
            $"( {avgType}: {this.Average avgType:G10} )"                

// Display a DataSet with three different format providers.
let displayDataSet (ds: DataSet) =
    let fmt obj1 obj2 obj3 obj4 = printfn $"{obj1,-12}{obj2,20}{obj3,20}{obj4,20}"
    let median = AverageInfo AverageType.Median
    let geMean =
        AverageInfo AverageType.GeometricMean

    // Display the dataset elements.
    if ds.Count > 0 then
        printf $"\nDataSet: [{ds[0]}"
        for i = 1 to ds.Count - 1 do
            printf $", {ds[i]}"
        printfn "]\n"

    fmt "Convert." "Default" "Geometric Mean" "Median"
    fmt "--------" "-------" "--------------" "------"
    fmt "ToBoolean"
        (Convert.ToBoolean(ds, null))
        (Convert.ToBoolean(ds, geMean))
        (Convert.ToBoolean(ds, median))
    fmt "ToByte"
        (Convert.ToByte(ds, null))
        (Convert.ToByte(ds, geMean))
        (Convert.ToByte(ds, median))
    fmt "ToChar"
        (Convert.ToChar(ds, null))
        (Convert.ToChar(ds, geMean))
        (Convert.ToChar(ds, median))
    printfn $"""{"ToDateTime",-12}{Convert.ToDateTime(ds, null).ToString "20:yyyy-MM-dd HH:mm:ss"}{Convert.ToDateTime(ds, geMean).ToString "20:yyyy-MM-dd HH:mm:ss"}{Convert.ToDateTime(ds, median).ToString "20:yyyy-MM-dd HH:mm:ss"}"""

    fmt "ToDecimal"
        (Convert.ToDecimal(ds, null))
        (Convert.ToDecimal(ds, geMean))
        (Convert.ToDecimal(ds, median))
    fmt "ToDouble"
        (Convert.ToDouble(ds, null))
        (Convert.ToDouble(ds, geMean))
        (Convert.ToDouble(ds, median))
    fmt "ToInt16"
        (Convert.ToInt16(ds, null))
        (Convert.ToInt16(ds, geMean))
        (Convert.ToInt16(ds, median))
    fmt "ToInt32"
        (Convert.ToInt32(ds, null))
        (Convert.ToInt32(ds, geMean))
        (Convert.ToInt32(ds, median))
    fmt "ToInt64"
        (Convert.ToInt64(ds, null))
        (Convert.ToInt64(ds, geMean))
        (Convert.ToInt64(ds, median))
    fmt "ToSByte"
        (Convert.ToSByte(ds, null))
        (Convert.ToSByte(ds, geMean))
        (Convert.ToSByte(ds, median))
    fmt "ToSingle"
        (Convert.ToSingle(ds, null))
        (Convert.ToSingle(ds, geMean))
        (Convert.ToSingle(ds, median))
    fmt "ToUInt16"
        (Convert.ToUInt16(ds, null))
        (Convert.ToUInt16(ds, geMean))
        (Convert.ToUInt16(ds, median))
    fmt "ToUInt32"
        (Convert.ToUInt32(ds, null))
        (Convert.ToUInt32(ds, geMean))
        (Convert.ToUInt32(ds, median))
    fmt "ToUInt64"
        (Convert.ToUInt64(ds, null))
        (Convert.ToUInt64(ds, geMean))
        (Convert.ToUInt64(ds, median))

printfn
    """This example of the Convert.To<Type>( object, IFormatprovider) methods 
generates the following output. The example displays the values 
returned by the methods, using several IFormatProvider objects.
"""

let ds1 = DataSet(10.5, 22.2, 45.9, 88.7, 156.05, 297.6)
displayDataSet ds1

let ds2 = DataSet(359999.95, 425000, 499999.5, 775000, 1695000)
displayDataSet ds2

// This example of the Convert.To<Type>( object, IFormatprovider) methods
// generates the following output. The example displays the values
// returned by the methods, using several IFormatProvider objects.
//
// DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
//
// Convert.                 Default      Geometric Mean              Median
// --------                 -------      --------------              ------
// ToBoolean                   True                True                True
// ToByte                       103                  59                  67
// ToChar                         g                   ;                   C
// ToDateTime   2003-05-13 15:04:12 2003-05-13 15:03:28 2003-05-13 15:03:35
// ToDecimal       103.491666666667    59.4332135445164                67.3
// ToDouble        103.491666666667    59.4332135445164                67.3
// ToInt16                      103                  59                  67
// ToInt32                      103                  59                  67
// ToInt64                      103                  59                  67
// ToSByte                      103                  59                  67
// ToSingle                103.4917            59.43321                67.3
// ToUInt16                     103                  59                  67
// ToUInt32                     103                  59                  67
// ToUInt64                     103                  59                  67
//
// DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
//
// Convert.                 Default      Geometric Mean              Median
// --------                 -------      --------------              ------
// ToBoolean                   True                True                True
// ToByte                       255                 255                 255
// ToChar                         ?                   ?                   ?
// ToDateTime   2003-05-22 07:39:08 2003-05-20 22:28:45 2003-05-19 09:55:48
// ToDecimal              750999.89    631577.237188435            499999.5
// ToDouble               750999.89    631577.237188435            499999.5
// ToInt16                    32767               32767               32767
// ToInt32                   751000              631577              500000
// ToInt64                   751000              631577              500000
// ToSByte                      127                 127                 127
// ToSingle                750999.9            631577.3            499999.5
// ToUInt16                   65535               65535               65535
// ToUInt32                  751000              631577              500000
// ToUInt64                  751000              631577              500000
Imports System.Collections

Module IConvertibleProviderDemo

    ' Define the types of averaging available in the class 
    ' implementing IConvertible.
    Enum AverageType as Short
        None = 0
        GeometricMean = 1
        ArithmeticMean = 2
        Median = 3
    End Enum

    ' Pass an instance of this class to methods that require an 
    ' IFormatProvider. The class instance determines the type of 
    ' average to calculate.
    Public Class AverageInfo
        Implements IFormatProvider

        Protected  AvgType      As AverageType

        ' Specify the type of averaging in the constructor.
        Public Sub New( avgType As AverageType )
            Me.AvgType = avgType
        End Sub

        ' This method returns a reference to the containing object 
        ' if an object of AverageInfo type is requested. 
        Public Function GetFormat( argType As Type ) As Object _
            Implements IFormatProvider.GetFormat

            If argType Is GetType( AverageInfo ) Then
                Return Me
            Else
                Return Nothing
            End If
        End Function 

        ' Use this property to set or get the type of averaging.
        Public Property TypeOfAverage( ) As AverageType
            Get
                Return Me.AvgType
            End Get
            Set( ByVal value as AverageType )
                Me.AvgType = value
            End Set
        End Property
    End Class 

    ' This class encapsulates an array of Double values and implements 
    ' the IConvertible interface. Most of the IConvertible methods 
    ' return an average of the array elements in one of three types: 
    ' arithmetic mean, geometric mean, or median. 
    Public Class DataSet
        Implements IConvertible

        Protected data              As ArrayList
        Protected defaultProvider   As AverageInfo
           
        ' Construct the object and add an initial list of values.
        ' Create a default format provider.
        Public Sub New( ParamArray values( ) As Double )
            data = New ArrayList( values )
            defaultProvider = New AverageInfo( _
                AverageType.ArithmeticMean )  
        End Sub
           
        ' Add additional values with this method.
        Public Function Add( value As Double ) As Integer
            data.Add( value )
            Return data.Count
        End Function
           
        ' Get, set, and add values with this indexer property.
        Default Public Property Item(index As Integer) As Double
            Get
                If index >= 0 AndAlso index < data.Count Then
                    Return System.Convert.ToDouble( data( index ) )
                Else
                    Throw New InvalidOperationException( _
                        "[DataSet.get] Index out of range." )
                End If
            End Get
            Set
                If index >= 0 AndAlso index < data.Count Then
                    data( index ) = value
                 
                ElseIf index = data.Count Then
                    data.Add( value )
                Else
                    Throw New InvalidOperationException( _
                        "[DataSet.set] Index out of range." )
                End If
            End Set
        End Property
          
        ' This property returns the number of elements in the object.
        Public ReadOnly Property Count( ) As Integer
            Get
                Return data.Count
            End Get
        End Property

        ' This method calculates the average of the object's elements.
        Protected Function Average( ByVal avgType As AverageType ) As Double

            Dim SumProd As Double 
            Dim Index   As Integer

            If data.Count = 0 Then Return 0.0

            Select Case avgType
                
                Case AverageType.GeometricMean

                    SumProd = 1.0
                    For Index = 0 To data.Count - 1
                        SumProd *= data( Index )
                    Next Index
                    
                    ' This calculation will not fail with negative 
                    ' elements.
                    Return Math.Sign( SumProd ) * Math.Pow( _
                        Math.Abs( SumProd ), 1.0 / data.Count )

                Case AverageType.ArithmeticMean

                    SumProd = 0.0
                    For Index = 0 To data.Count - 1
                        SumProd += data( Index )
                    Next Index

                    Return SumProd / data.Count 

                Case AverageType.Median

                    If data.Count Mod 2 = 0 Then
                        Return ( data( data.Count \ 2 ) + _
                            data( data.Count \ 2 - 1 ) ) / 2.0
                    Else
                        Return data( data.Count \ 2 ) 
                    End If
            End Select
        End Function

        ' Get the AverageInfo object from the caller's format 
        ' provider, or use the local default.
        Protected Function GetAverageInfo( _
            provider As IFormatProvider ) As AverageInfo

            Dim avgInfo As AverageInfo = Nothing

            If Not provider Is Nothing Then
                avgInfo = provider.GetFormat( GetType( AverageInfo ) )
            End If

            Return IIf( avgInfo Is Nothing, defaultProvider, avgInfo )
            
        End Function           

        ' Calculate the average and limit the range.
        Protected Function CalcNLimitAverage( min As Double, _
            max As Double, provider as IFormatProvider ) As Double

            ' Get the format provider and calculate the average.
            Dim avgInfo As AverageInfo = GetAverageInfo( provider )
            Dim avg As Double = Average( avgInfo.TypeOfAverage )

            ' Limit the range, based on the minimum and maximum values 
            ' for the type.
            Return IIf( avg > max, max, IIf( avg < min, min, avg ) )

        End Function

        ' The following elements are required by IConvertible.

        ' None of these conversion functions throw exceptions. When
        ' the data is out of range for the type, the appropriate
        ' MinValue or MaxValue is used.
        Public Function GetTypeCode( ) As TypeCode _
            Implements IConvertible.GetTypeCode
            Return TypeCode.Object
        End Function

        Function ToBoolean( ByVal provider As IFormatProvider ) As _
            Boolean Implements IConvertible.ToBoolean

            ' ToBoolean is false if the dataset is empty.
            If data.Count <= 0 Then
                Return False

            ' For median averaging, ToBoolean is true if any 
            ' non-discarded elements are nonzero.
            ElseIf AverageType.Median = _
                GetAverageInfo( provider ).TypeOfAverage Then

                If data.Count Mod 2 = 0 Then
                    Return ( data( data.Count \ 2 ) <> 0.0 Or _
                        data( data.Count \ 2 - 1 ) <> 0.0 )
                Else
                    Return data( data.Count \ 2 ) <> 0.0
                End If

            ' For arithmetic or geometric mean averaging, ToBoolean is 
            ' true if any element of the dataset is nonzero.  
            Else
                Dim Index As Integer
                For Index = 0 To data.Count - 1
                    If data( Index ) <> 0.0 Then Return True
                Next Index
                Return False
            End If
        End Function

        Function ToByte( ByVal provider As IFormatProvider ) As Byte _
            Implements IConvertible.ToByte
            Return Convert.ToByte( CalcNLimitAverage( _
                Byte.MinValue, Byte.MaxValue, provider ) )
        End Function

        Function ToChar( ByVal provider As IFormatProvider ) As Char _
            Implements IConvertible.ToChar
            Return Convert.ToChar( Convert.ToUInt16( _
                CalcNLimitAverage( 0.0, &HFFFF, provider ) ) )
        End Function

        ' Convert to DateTime by adding the calculated average as 
        ' seconds to the current date and time. A valid DateTime is 
        ' always returned.
        Function ToDateTime( ByVal provider As IFormatProvider ) As _
            DateTime Implements IConvertible.ToDateTime
            Dim seconds As Double = Average( _
                GetAverageInfo( provider ).TypeOfAverage )
            Try
                Return DateTime.Now.AddSeconds( seconds )
            Catch ex As ArgumentOutOfRangeException 
                Return IIf( seconds < 0.0, DateTime.MinValue, _
                    DateTime.MaxValue )
            End Try
        End Function

        Function ToDecimal( ByVal provider As IFormatProvider ) As _
            Decimal Implements IConvertible.ToDecimal

            ' The Double conversion rounds Decimal.MinValue and
            ' Decimal.MaxValue to invalid Decimal values, so the 
            ' following limits must be used.
            Return Convert.ToDecimal( CalcNLimitAverage( _
                -79228162514264330000000000000.0, _
                79228162514264330000000000000.0, provider ) )
        End Function

        Function ToDouble( ByVal provider As IFormatProvider) As _
            Double Implements IConvertible.ToDouble
            Return Average( GetAverageInfo( provider ).TypeOfAverage )
        End Function

        Function ToInt16( ByVal provider As IFormatProvider ) As _
            Short Implements IConvertible.ToInt16
            Return Convert.ToInt16( CalcNLimitAverage( _
                Int16.MinValue, Int16.MaxValue, provider ) )
        End Function

        Function ToInt32( ByVal provider As IFormatProvider ) As _
            Integer Implements IConvertible.ToInt32
            Return Convert.ToInt32( CalcNLimitAverage( _
                Int32.MinValue, Int32.MaxValue, provider ) )
        End Function

        Function ToInt64( ByVal provider As IFormatProvider ) As Long _
            Implements IConvertible.ToInt64

            ' The Double conversion rounds Int64.MinValue and 
            ' Int64.MaxValue to invalid Long values, so the following 
            ' limits must be used.
            Return Convert.ToInt64( CalcNLimitAverage( _
                -9223372036854775000, 9223372036854775000, provider ) )
        End Function

        Function ToSByte( ByVal provider As IFormatProvider ) As _
            SByte Implements IConvertible.ToSByte

            ' SByte.MinValue and SByte.MaxValue are not defined in
            ' Visual Basic.
            Return Convert.ToSByte( CalcNLimitAverage( _
                -128, 127, provider ) )
        End Function

        Function ToSingle( ByVal provider As IFormatProvider ) As _
            Single Implements IConvertible.ToSingle
            Return Convert.ToSingle( CalcNLimitAverage( _
                Single.MinValue, Single.MaxValue, provider ) )
        End Function

        Function ToUInt16( ByVal provider As IFormatProvider ) As _
            UInt16 Implements IConvertible.ToUInt16

            ' UInt16.MinValue and UInt16.MaxValue are not defined in 
            ' Visual Basic.
            Return Convert.ToUInt16( CalcNLimitAverage( _
                0, &HFFFF, provider ) )
        End Function

        Function ToUInt32( ByVal provider As IFormatProvider ) As _
            UInt32 Implements IConvertible.ToUInt32

            ' UInt32.MinValue and UInt32.MaxValue are not defined in 
            ' Visual Basic.
            Return Convert.ToUInt32( CalcNLimitAverage( _
                0, 4294967295, provider ) )
        End Function

        Function ToUInt64( ByVal provider As IFormatProvider ) As _
            UInt64 Implements IConvertible.ToUInt64

            ' UInt64.MinValue and UInt64.MaxValue are not defined in 
            ' Visual Basic. The Double conversion would have rounded 
            ' UInt64.MaxValue, so the following limit must be used.
            Return Convert.ToUInt64( CalcNLimitAverage( _
                0, 18446744073709550000.0, provider ) )
        End Function

        Function ToType( ByVal conversionType As Type, _
            ByVal provider As IFormatProvider) As Object _
            Implements IConvertible.ToType
            Return Convert.ChangeType( Average( GetAverageInfo( _
                provider ).TypeOfAverage ), conversionType )
        End Function

        Overloads Function ToString( ByVal provider As IFormatProvider _
            ) As String Implements IConvertible.ToString
            Dim avgType as AverageType = _
                GetAverageInfo( provider ).TypeOfAverage
            Return String.Format( "( {0}: {1:G10} )", avgType, _
                Average( avgType ) )
        End Function
    End Class
   
    ' Display a DataSet with three different format providers.
    Sub DisplayDataSet( ds As DataSet )

        Dim fmt    As String      = "{0,-12}{1,20}{2,20}{3,20}"
        Dim median As AverageInfo = New AverageInfo( AverageType.Median )
        Dim geMean As AverageInfo = _
            New AverageInfo( AverageType.GeometricMean )
        Dim iX     As Integer

        ' Display the dataset elements.
        If ds.Count > 0 Then
            Console.Write( vbCrLf & "DataSet: [{0}", ds( 0 ) )
            For iX = 1 To ds.Count - 1
                Console.Write( ", {0}", ds( iX ) )
            Next iX
            Console.WriteLine( "]" & vbCrLf )
        End If

        Console.WriteLine( fmt, "Convert.", "Default", _
            "Geometric Mean", "Median" )
        Console.WriteLine( fmt, "--------", "-------", _
            "--------------", "------" )
        Console.WriteLine( fmt, "ToBoolean", _
            Convert.ToBoolean( ds, Nothing ), _
            Convert.ToBoolean( ds, geMean ), _
            Convert.ToBoolean( ds, median ) )
        Console.WriteLine( fmt, "ToByte", _
            Convert.ToByte( ds, Nothing ), _
            Convert.ToByte( ds, geMean ), _
            Convert.ToByte( ds, median ) )
        Console.WriteLine( fmt, "ToChar", _
            Convert.ToChar( ds, Nothing ), _
            Convert.ToChar( ds, geMean ), _
            Convert.ToChar( ds, median ) )
        Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" & _
            "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", _
            "ToDateTime", Convert.ToDateTime( ds, Nothing ), _
            Convert.ToDateTime( ds, geMean ), _
            Convert.ToDateTime( ds, median ) )
        Console.WriteLine( fmt, "ToDecimal", _
            Convert.ToDecimal( ds, Nothing ), _
            Convert.ToDecimal( ds, geMean ), _
            Convert.ToDecimal( ds, median ) )
        Console.WriteLine( fmt, "ToDouble", _
            Convert.ToDouble( ds, Nothing ), _
            Convert.ToDouble( ds, geMean ), _
            Convert.ToDouble( ds, median ) )
        Console.WriteLine( fmt, "ToInt16", _
            Convert.ToInt16( ds, Nothing ), _
            Convert.ToInt16( ds, geMean ), _
            Convert.ToInt16( ds, median ) )
        Console.WriteLine( fmt, "ToInt32", _
            Convert.ToInt32( ds, Nothing ), _
            Convert.ToInt32( ds, geMean ), _
            Convert.ToInt32( ds, median ) )
        Console.WriteLine( fmt, "ToInt64", _
            Convert.ToInt64( ds, Nothing ), _
            Convert.ToInt64( ds, geMean ), _
            Convert.ToInt64( ds, median ) )
        Console.WriteLine( fmt, "ToSByte", _
            Convert.ToSByte( ds, Nothing ), _
            Convert.ToSByte( ds, geMean ), _
            Convert.ToSByte( ds, median ) )
        Console.WriteLine( fmt, "ToSingle", _
            Convert.ToSingle( ds, Nothing ), _
            Convert.ToSingle( ds, geMean ), _
            Convert.ToSingle( ds, median ) )
        Console.WriteLine( fmt, "ToUInt16", _
            Convert.ToUInt16( ds, Nothing ), _
            Convert.ToUInt16( ds, geMean ), _
            Convert.ToUInt16( ds, median ) )
        Console.WriteLine( fmt, "ToUInt32", _
            Convert.ToUInt32( ds, Nothing ), _
            Convert.ToUInt32( ds, geMean ), _
            Convert.ToUInt32( ds, median ) )
        Console.WriteLine( fmt, "ToUInt64", _
            Convert.ToUInt64( ds, Nothing ), _
            Convert.ToUInt64( ds, geMean ), _
            Convert.ToUInt64( ds, median ) )
    End Sub
   
    Sub Main( )
        Console.WriteLine( _
            "This example of the Convert.To<Type>( Object, " & _
            "IFormatProvider ) methods " & vbCrLf & "generates " & _
            "the following output. The example displays the " & _
            "values " & vbCrLf & "returned by the methods, " & _
            "using several IFormatProvider objects." & vbCrLf )
          
        Dim ds1 As New DataSet( 10.5, 22.2, 45.9, 88.7, 156.05, 297.6 )
        DisplayDataSet( ds1 )
          
        Dim ds2 As New DataSet( _
            359999.95, 425000, 499999.5, 775000, 1695000 )
        DisplayDataSet( ds2 )
    End Sub 
End Module 

' This example of the Convert.To<Type>( Object, IFormatProvider ) methods
' generates the following output. The example displays the values
' returned by the methods, using several IFormatProvider objects.
' 
' DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
' 
' Convert.                 Default      Geometric Mean              Median
' --------                 -------      --------------              ------
' ToBoolean                   True                True                True
' ToByte                       103                  59                  67
' ToChar                         g                   ;                   C
' ToDateTime   2003-05-13 14:52:53 2003-05-13 14:52:09 2003-05-13 14:52:17
' ToDecimal       103.491666666667    59.4332135445164                67.3
' ToDouble        103.491666666667    59.4332135445164                67.3
' ToInt16                      103                  59                  67
' ToInt32                      103                  59                  67
' ToInt64                      103                  59                  67
' ToSByte                      103                  59                  67
' ToSingle                103.4917            59.43321                67.3
' ToUInt16                     103                  59                  67
' ToUInt32                     103                  59                  67
' ToUInt64                     103                  59                  67
' 
' DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
' 
' Convert.                 Default      Geometric Mean              Median
' --------                 -------      --------------              ------
' ToBoolean                   True                True                True
' ToByte                       255                 255                 255
' ToChar                         ?                   ?                   ?
' ToDateTime   2003-05-22 07:27:49 2003-05-20 22:17:27 2003-05-19 09:44:29
' ToDecimal              750999.89    631577.237188435            499999.5
' ToDouble               750999.89    631577.237188435            499999.5
' ToInt16                    32767               32767               32767
' ToInt32                   751000              631577              500000
' ToInt64                   751000              631577              500000
' ToSByte                      127                 127                 127
' ToSingle                750999.9            631577.3            499999.5
' ToUInt16                   65535               65535               65535
' ToUInt32                  751000              631577              500000
' ToUInt64                  751000              631577              500000

注解

provider 使用户能够指定有关 value内容区域性特定的转换信息。 例如,如果 value 一个 String 表示数字, provider 可以提供有关用于表示该数字的表示法的区域性特定信息。

基类型忽略 provider;但是,如果 value 参数是实现接口的用户定义类型,可以使用此参数 IConvertible

适用于

ToInt16(UInt64)

重要

此 API 不符合 CLS。

将指定的 64 位无符号整数的值转换为等效的 16 位有符号整数。

public:
 static short ToInt16(System::UInt64 value);
[System.CLSCompliant(false)]
public static short ToInt16 (ulong value);
[<System.CLSCompliant(false)>]
static member ToInt16 : uint64 -> int16
Public Shared Function ToInt16 (value As ULong) As Short

参数

value
UInt64

要转换的 64 位无符号整数。

返回

Int16

一个与 value 等效的 16 位带符号整数。

属性

例外

示例

以下示例尝试将无符号长整数数组中的每个元素转换为 16 位有符号整数。

ulong[] numbers = { UInt64.MinValue, 121, 340, UInt64.MaxValue };
short result;

foreach (ulong number in numbers)
{
   try {
      result = Convert.ToInt16(number);
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt64 value 0 to a Int16 value 0.
//    Converted the UInt64 value 121 to a Int16 value 121.
//    Converted the UInt64 value 340 to a Int16 value 340.
//    The UInt64 value 18446744073709551615 is outside the range of the Int16 type.
let numbers = 
    [| UInt64.MinValue; 121uL; 340uL; UInt64.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt16 number
        printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int16 type."
// The example displays the following output:
//    Converted the UInt64 value 0 to a Int16 value 0.
//    Converted the UInt64 value 121 to a Int16 value 121.
//    Converted the UInt64 value 340 to a Int16 value 340.
//    The UInt64 value 18446744073709551615 is outside the range of the Int16 type.
Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As Short
For Each number As ULong In numbers
   Try
      result = Convert.ToInt16(number)
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt64 value 0 to a Int16 value 0.
'    Converted the UInt64 value 121 to a Int16 value 121.
'    Converted the UInt64 value 340 to a Int16 value 340.
'    The UInt64 value 18446744073709551615 is outside the range of the Int16 type.

适用于

ToInt16(UInt32)

重要

此 API 不符合 CLS。

将指定的 32 位无符号整数的值转换为等效的 16 位有符号整数。

public:
 static short ToInt16(System::UInt32 value);
[System.CLSCompliant(false)]
public static short ToInt16 (uint value);
[<System.CLSCompliant(false)>]
static member ToInt16 : uint32 -> int16
Public Shared Function ToInt16 (value As UInteger) As Short

参数

value
UInt32

要转换的 32 位无符号整数。

返回

Int16

一个与 value 等效的 16 位带符号整数。

属性

例外

示例

以下示例尝试将无符号整数数组中的每个元素转换为 16 位有符号整数。

uint[] numbers = { UInt32.MinValue, 121, 340, UInt32.MaxValue };
short result;

foreach (uint number in numbers)
{
   try {
      result = Convert.ToInt16(number);
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt32 value 0 to a Int16 value 0.
//    Converted the UInt32 value 121 to a Int16 value 121.
//    Converted the UInt32 value 340 to a Int16 value 340.
//    The UInt32 value 4294967295 is outside the range of the Int16 type.
let numbers =
    [| UInt32.MinValue; 121u; 340u; UInt32.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt16 number
        printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int16 type."
// The example displays the following output:
//    Converted the UInt32 value 0 to a Int16 value 0.
//    Converted the UInt32 value 121 to a Int16 value 121.
//    Converted the UInt32 value 340 to a Int16 value 340.
//    The UInt32 value 4294967295 is outside the range of the Int16 type.
Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As Short
For Each number As UInteger In numbers
   Try
      result = Convert.ToInt16(number)
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt32 value 0 to a Int16 value 0.
'    Converted the UInt32 value 121 to a Int16 value 121.
'    Converted the UInt32 value 340 to a Int16 value 340.
'    The UInt32 value 4294967295 is outside the range of the Int16 type.

适用于

ToInt16(UInt16)

重要

此 API 不符合 CLS。

将指定的 16 位无符号整数的值转换为等效的 16 位有符号整数。

public:
 static short ToInt16(System::UInt16 value);
[System.CLSCompliant(false)]
public static short ToInt16 (ushort value);
[<System.CLSCompliant(false)>]
static member ToInt16 : uint16 -> int16
Public Shared Function ToInt16 (value As UShort) As Short

参数

value
UInt16

要转换的 16 位无符号整数。

返回

Int16

一个与 value 等效的 16 位带符号整数。

属性

例外

示例

以下示例尝试将无符号 16 位整数数组中的每个元素转换为 16 位有符号整数。

ushort[] numbers = { UInt16.MinValue, 121, 340, UInt16.MaxValue };
short result;
foreach (ushort number in numbers)
{
   try {
      result = Convert.ToInt16(number);
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//       Converted the UInt16 value 0 to a Int16 value 0.
//       Converted the UInt16 value 121 to a Int16 value 121.
//       Converted the UInt16 value 340 to a Int16 value 340.
//       The UInt16 value 65535 is outside the range of the Int16 type.
let numbers = 
    [| UInt16.MinValue; 121us; 340us; UInt16.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt16 number
        printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int16 type."
// The example displays the following output:
//       Converted the UInt16 value 0 to a Int16 value 0.
//       Converted the UInt16 value 121 to a Int16 value 121.
//       Converted the UInt16 value 340 to a Int16 value 340.
//       The UInt16 value 65535 is outside the range of the Int16 type.
Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As Short
For Each number As UShort In numbers
   Try
      result = Convert.ToInt16(number)
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'       Converted the UInt16 value 0 to a Int16 value 0.
'       Converted the UInt16 value 121 to a Int16 value 121.
'       Converted the UInt16 value 340 to a Int16 value 340.
'       The UInt16 value 65535 is outside the range of the Int16 type.

适用于

ToInt16(String)

将数字的指定字符串表示形式转换为等效的 16 位带符号整数。

public:
 static short ToInt16(System::String ^ value);
public static short ToInt16 (string value);
public static short ToInt16 (string? value);
static member ToInt16 : string -> int16
Public Shared Function ToInt16 (value As String) As Short

参数

value
String

包含要转换的数字的字符串。

返回

Int16

一个与 value 中数字等效的 16 位带符号整数,如果 valuenull,则为 0(零)。

例外

value 不由一个可选符号后跟一系列数字 (0-9) 组成。

value 表示小于 Int16.MinValue 或大于 Int16.MaxValue 的数字。

示例

以下示例使用默认格式将 16 位整数的字符串表示形式转换为 ToInt16 该方法。

// Example of the Convert::ToInt16( String* ) and 
// Convert::ToInt16( String*, IFormatProvider* ) methods.
using namespace System;
using namespace System::Globalization;
const __wchar_t * protoFmt = L"{0,-20}{1,-20}{2}";

// Get the exception type name; remove the namespace prefix.
String^ GetExceptionType( Exception^ ex )
{
   String^ exceptionType = ex->GetType()->ToString();
   return exceptionType->Substring( exceptionType->LastIndexOf( '.' ) + 1 );
}

void ConvertToInt16( String^ numericStr, IFormatProvider^ provider )
{
   Object^ defaultValue;
   Object^ providerValue;
   
   // Convert numericStr to Int16 without a format provider.
   try
   {
      defaultValue = Convert::ToInt16( numericStr );
   }
   catch ( Exception^ ex ) 
   {
      defaultValue = GetExceptionType( ex );
   }

   
   // Convert numericStr to Int16 with a format provider.
   try
   {
      providerValue = Convert::ToInt16( numericStr, provider );
   }
   catch ( Exception^ ex ) 
   {
      providerValue = GetExceptionType( ex );
   }

   Console::WriteLine( gcnew String( protoFmt ), numericStr, defaultValue, providerValue );
}

int main()
{
   
   // Create a NumberFormatInfo object and set several of its
   // properties that apply to numbers.
   NumberFormatInfo^ provider = gcnew NumberFormatInfo;
   
   // These properties affect the conversion.
   provider->NegativeSign = "neg ";
   provider->PositiveSign = "pos ";
   
   // These properties do not affect the conversion.
   // The input string cannot have decimal and group separators.
   provider->NumberDecimalSeparator = ".";
   provider->NumberGroupSeparator = ",";
   array<Int32>^sizes = {3};
   provider->NumberGroupSizes = sizes;
   provider->NumberNegativePattern = 0;
   Console::WriteLine( "This example of\n"
   "  Convert::ToInt16( String* ) and \n"
   "  Convert::ToInt16( String*, IFormatProvider* ) "
   "\ngenerates the following output. It converts "
   "several strings to \nshort values, using "
   "default formatting or a NumberFormatInfo object.\n" );
   Console::WriteLine( gcnew String( protoFmt ), "String to convert", "Default/exception", "Provider/exception" );
   Console::WriteLine( gcnew String( protoFmt ), "-----------------", "-----------------", "------------------" );
   
   // Convert strings, with and without an IFormatProvider.
   ConvertToInt16( "12345", provider );
   ConvertToInt16( "+12345", provider );
   ConvertToInt16( "pos 12345", provider );
   ConvertToInt16( "-12345", provider );
   ConvertToInt16( "neg 12345", provider );
   ConvertToInt16( "12345.", provider );
   ConvertToInt16( "12,345", provider );
   ConvertToInt16( "(12345)", provider );
   ConvertToInt16( "32768", provider );
   ConvertToInt16( "-32769", provider );
}

/*
This example of
  Convert::ToInt16( String* ) and
  Convert::ToInt16( String*, IFormatProvider* )
generates the following output. It converts several strings to
short values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
12345               12345               12345
+12345              12345               FormatException
pos 12345           FormatException     12345
-12345              -12345              FormatException
neg 12345           FormatException     -12345
12345.              FormatException     FormatException
12,345              FormatException     FormatException
(12345)             FormatException     FormatException
32768               OverflowException   OverflowException
-32769              OverflowException   FormatException
*/
// Example of the Convert.ToInt16( string ) and
// Convert.ToInt16( string, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToInt16ProviderDemo
{
    static string format = "{0,-20}{1,-20}{2}";

     // Get the exception type name; remove the namespace prefix.
    static string GetExceptionType( Exception ex )
    {
        string exceptionType = ex.GetType( ).ToString( );
        return exceptionType.Substring(
            exceptionType.LastIndexOf( '.' ) + 1 );
    }

    static void ConvertToInt16( string numericStr,
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

        // Convert numericStr to Int16 without a format provider.
        try
        {
            defaultValue = Convert.ToInt16( numericStr );
        }
        catch( Exception ex )
        {
            defaultValue = GetExceptionType( ex );
        }

        // Convert numericStr to Int16 with a format provider.
        try
        {
            providerValue = Convert.ToInt16( numericStr, provider );
        }
        catch( Exception ex )
        {
            providerValue = GetExceptionType( ex );
        }

        Console.WriteLine( format, numericStr,
            defaultValue, providerValue );
    }

    public static void Main( )
    {
        // Create a NumberFormatInfo object and set several of its
        // properties that apply to numbers.
        NumberFormatInfo provider = new NumberFormatInfo();

        // These properties affect the conversion.
        provider.NegativeSign = "neg ";
        provider.PositiveSign = "pos ";

        // These properties do not affect the conversion.
        // The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = ".";
        provider.NumberGroupSeparator = ",";
        provider.NumberGroupSizes = new int[ ] { 3 };
        provider.NumberNegativePattern = 0;

        Console.WriteLine("This example of\n" +
            "  Convert.ToInt16( string ) and \n" +
            "  Convert.ToInt16( string, IFormatProvider ) " +
            "\ngenerates the following output. It converts " +
            "several strings to \nshort values, using " +
            "default formatting or a NumberFormatInfo object.\n" );
        Console.WriteLine( format, "String to convert",
            "Default/exception", "Provider/exception" );
        Console.WriteLine( format, "-----------------",
            "-----------------", "------------------" );

        // Convert strings, with and without an IFormatProvider.
        ConvertToInt16( "12345", provider );
        ConvertToInt16( "+12345", provider );
        ConvertToInt16( "pos 12345", provider );
        ConvertToInt16( "-12345", provider );
        ConvertToInt16( "neg 12345", provider );
        ConvertToInt16( "12345.", provider );
        ConvertToInt16( "12,345", provider );
        ConvertToInt16( "(12345)", provider );
        ConvertToInt16( "32768", provider );
        ConvertToInt16( "-32769", provider );
    }
}

/*
This example of
  Convert.ToInt16( string ) and
  Convert.ToInt16( string, IFormatProvider )
generates the following output. It converts several strings to
short values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
12345               12345               12345
+12345              12345               FormatException
pos 12345           FormatException     12345
-12345              -12345              FormatException
neg 12345           FormatException     -12345
12345.              FormatException     FormatException
12,345              FormatException     FormatException
(12345)             FormatException     FormatException
32768               OverflowException   OverflowException
-32769              OverflowException   FormatException
*/
// Example of the Convert.ToInt16( string ) and
// Convert.ToInt16( string, IFormatProvider ) methods.
open System
open System.Globalization

let format obj1 obj2 obj3 = printfn $"{obj1,-20}{obj2,-20}{obj3}"

// Get the exception type name; remove the namespace prefix.
let getExceptionType (ex: exn) =
    let exceptionType = ex.GetType() |> string
    exceptionType.Substring(exceptionType.LastIndexOf '.' + 1)

let convertToInt16 (numericStr: string) (provider: IFormatProvider) =
    // Convert numericStr to Int16 without a format provider.
    let defaultValue = 
        try
            Convert.ToInt16 numericStr
            |> string
        with ex ->
            getExceptionType ex

    // Convert numericStr to Int16 with a format provider.
    let providerValue = 
        try
            Convert.ToInt16(numericStr, provider)
            |> string
        with ex ->
            getExceptionType ex

    format numericStr defaultValue providerValue

// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
let provider = NumberFormatInfo()

// These properties affect the conversion.
provider.NegativeSign <- "neg "
provider.PositiveSign <- "pos "

// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator <- "."
provider.NumberGroupSeparator <- ","
provider.NumberGroupSizes <- [| 3 |]
provider.NumberNegativePattern <- 0

printfn
    """This example of
  Convert.ToInt16( string ) and 
  Convert.ToInt16( string, IFormatProvider ) 
generates the following output. It converts several strings to 
short values, using default formatting or a NumberFormatInfo object.
"""
format "String to convert" "Default/exception" "Provider/exception"
format "-----------------" "-----------------" "------------------"

// Convert strings, with and without an IFormatProvider.
convertToInt16 "12345" provider
convertToInt16 "+12345" provider
convertToInt16 "pos 12345" provider
convertToInt16 "-12345" provider
convertToInt16 "neg 12345" provider
convertToInt16 "12345." provider
convertToInt16 "12,345" provider
convertToInt16 "(12345)" provider
convertToInt16 "32768" provider
convertToInt16 "-32769" provider

// This example of
//   Convert.ToInt16( string ) and
//   Convert.ToInt16( string, IFormatProvider )
// generates the following output. It converts several strings to
// short values, using default formatting or a NumberFormatInfo object.
//
// String to convert   Default/exception   Provider/exception
// -----------------   -----------------   ------------------
// 12345               12345               12345
// +12345              12345               FormatException
// pos 12345           FormatException     12345
// -12345              -12345              FormatException
// neg 12345           FormatException     -12345
// 12345.              FormatException     FormatException
// 12,345              FormatException     FormatException
// (12345)             FormatException     FormatException
// 32768               OverflowException   OverflowException
// -32769              OverflowException   FormatException
' Example of the Convert.ToInt16( String ) and 
' Convert.ToInt16( String, IFormatProvider ) methods.
Imports System.Globalization

Module ToInt16ProviderDemo

    Dim format As String = "{0,-20}{1,-20}{2}"

    ' Get the exception type name; remove the namespace prefix.
    Function GetExceptionType( ex As Exception ) As String

        Dim exceptionType   As String = ex.GetType( ).ToString( )
        Return exceptionType.Substring( _
            exceptionType.LastIndexOf( "."c ) + 1 )
    End Function

    Sub ConvertToInt16( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

        ' Convert numericStr to Int16 without a format provider.
        Try
            defaultValue = Convert.ToInt16( numericStr )
        Catch ex As Exception
            defaultValue = GetExceptionType( ex )
        End Try

        ' Convert numericStr to Int16 with a format provider.
        Try
            providerValue = Convert.ToInt16( numericStr, provider )
        Catch ex As Exception
            providerValue = GetExceptionType( ex )
        End Try

        Console.WriteLine( format, numericStr, _
            defaultValue, providerValue )
    End Sub

    Sub Main( )

        ' Create a NumberFormatInfo object and set several of its
        ' properties that apply to numbers.
        Dim provider  As NumberFormatInfo = new NumberFormatInfo( )

        ' These properties affect the conversion.
        provider.NegativeSign = "neg "
        provider.PositiveSign = "pos "

        ' These properties do not affect the conversion.
        ' The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = "."
        provider.NumberGroupSeparator = ","
        provider.NumberGroupSizes = New Integer( ) { 3 }
        provider.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToInt16( String ) and " & vbCrLf & _
            "  Convert.ToInt16( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "Short " & _
            "values, using default formatting " & _
            "or a NumberFormatInfo object." & vbCrLf )
        Console.WriteLine( format, "String to convert", _
            "Default/exception", "Provider/exception" )
        Console.WriteLine( format, "-----------------", _
            "-----------------", "------------------" )

        ' Convert strings, with and without an IFormatProvider.
        ConvertToInt16( "12345", provider )
        ConvertToInt16( "+12345", provider )
        ConvertToInt16( "pos 12345", provider )
        ConvertToInt16( "-12345", provider )
        ConvertToInt16( "neg 12345", provider )
        ConvertToInt16( "12345.", provider )
        ConvertToInt16( "12,345", provider )
        ConvertToInt16( "(12345)", provider )
        ConvertToInt16( "32768", provider )
        ConvertToInt16( "-32769", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToInt16( String ) and
'   Convert.ToInt16( String, IFormatProvider )
' generates the following output. It converts several strings to
' Short values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 12345               12345               12345
' +12345              12345               FormatException
' pos 12345           FormatException     12345
' -12345              -12345              FormatException
' neg 12345           FormatException     -12345
' 12345.              FormatException     FormatException
' 12,345              FormatException     FormatException
' (12345)             FormatException     FormatException
' 32768               OverflowException   OverflowException
' -32769              OverflowException   FormatException

注解

使用该方法ToInt16(String)等效于传递给valueInt16.Parse(String)该方法。 value 通过使用当前区域性的格式设置约定进行解释。

如果不想在转换失败时处理异常,可以改为调用 Int16.TryParse 该方法。 它返回一个 Boolean 值,该值指示转换是成功还是失败。

另请参阅

适用于

ToInt16(Single)

将指定的单精度浮点数的值转换为等效的 16 位带符号整数。

public:
 static short ToInt16(float value);
public static short ToInt16 (float value);
static member ToInt16 : single -> int16
Public Shared Function ToInt16 (value As Single) As Short

参数

value
Single

要转换的单精度浮点数。

返回

Int16

value,舍入为最接近的 16 位带符号整数。 如果 value 为两个整数中间的数字,则返回二者中的偶数;即 4.5 转换为 4,而 5.5 转换为 6。

例外

value 大于 Int16.MaxValue 或小于 Int16.MinValue

示例

以下示例尝试将值数组 Single 中的每个元素转换为 16 位有符号整数。

float[] values = { Single.MinValue, -1.38e10f, -1023.299f, -12.98f,
                   0f, 9.113e-16f, 103.919f, 17834.191f, Single.MaxValue };
short result;

foreach (float value in values)
{
   try {
      result = Convert.ToInt16(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value, result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int16 type.", value);
   }
}
// The example displays the following output:
//    -3.4028235E+38 is outside the range of the Int16 type.
//    -1.38E+10 is outside the range of the Int16 type.
//    Converted the Single value -1023.299 to the Int16 value -1023.
//    Converted the Single value -12.98 to the Int16 value -13.
//    Converted the Single value 0 to the Int16 value 0.
//    Converted the Single value 9.113E-16 to the Int16 value 0.
//    Converted the Single value 103.919 to the Int16 value 104.
//    Converted the Single value 17834.191 to the Int16 value 17834.
//    3.4028235E+38 is outside the range of the Int16 type.
let values = 
    [| Single.MinValue; -1.38e10f; -1023.299f; -12.98f
       0f; 9.113e-16f; 103.919f; 17834.191f; Single.MaxValue |]

for value in values do
    try
        let result = Convert.ToInt16 value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the Int16 type."
// The example displays the following output:
//    -3.4028235E+38 is outside the range of the Int16 type.
//    -1.38E+10 is outside the range of the Int16 type.
//    Converted the Single value -1023.299 to the Int16 value -1023.
//    Converted the Single value -12.98 to the Int16 value -13.
//    Converted the Single value 0 to the Int16 value 0.
//    Converted the Single value 9.113E-16 to the Int16 value 0.
//    Converted the Single value 103.919 to the Int16 value 104.
//    Converted the Single value 17834.191 to the Int16 value 17834.
//    3.4028235E+38 is outside the range of the Int16 type.
Dim values() As Single = { Single.MinValue, -1.38e10, -1023.299, -12.98, _
                           0, 9.113e-16, 103.919, 17834.191, Single.MaxValue }
Dim result As Short

For Each value As Single In values
   Try
      result = Convert.ToInt16(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int16 type.", value)
   End Try
Next
' The example displays the following output:
'    -3.402823E+38 is outside the range of the Int16 type.
'    -1.38E+10 is outside the range of the Int16 type.
'    Converted the Single value -1023.299 to the Int16 value -1023.
'    Converted the Single value -12.98 to the Int16 value -13.
'    Converted the Single value 0 to the Int16 value 0.
'    Converted the Single value 9.113E-16 to the Int16 value 0.
'    Converted the Single value 103.919 to the Int16 value 104.
'    Converted the Single value 17834.19 to the Int16 value 17834.
'    3.402823E+38 is outside the range of the Int16 type.

另请参阅

适用于

ToInt16(SByte)

重要

此 API 不符合 CLS。

将指定的 8 位带符号整数的值转换为等效的 16 位带符号整数。

public:
 static short ToInt16(System::SByte value);
[System.CLSCompliant(false)]
public static short ToInt16 (sbyte value);
[<System.CLSCompliant(false)>]
static member ToInt16 : sbyte -> int16
Public Shared Function ToInt16 (value As SByte) As Short

参数

value
SByte

要转换的 8 位带符号整数。

返回

Int16

一个与 value 等效的 8 位带符号整数。

属性

示例

以下示例将带符号字节数组中的每个元素转换为 16 位有符号整数。

sbyte[] numbers = { SByte.MinValue, -1, 0, 10, SByte.MaxValue };
short result;

foreach (sbyte number in numbers)
{
   result = Convert.ToInt16(number);
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                     number.GetType().Name, number,
                     result.GetType().Name, result);
}
// The example displays the following output:
//       Converted the SByte value -128 to the Int16 value -128.
//       Converted the SByte value -1 to the Int16 value -1.
//       Converted the SByte value 0 to the Int16 value 0.
//       Converted the SByte value 10 to the Int16 value 10.
//       Converted the SByte value 127 to the Int16 value 127.
let numbers = 
    [| SByte.MinValue; -1y; 0y; 10y; SByte.MaxValue |]

for number in numbers do
    let result = Convert.ToInt16 number
    printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
// The example displays the following output:
//       Converted the SByte value -128 to the Int16 value -128.
//       Converted the SByte value -1 to the Int16 value -1.
//       Converted the SByte value 0 to the Int16 value 0.
//       Converted the SByte value 10 to the Int16 value 10.
//       Converted the SByte value 127 to the Int16 value 127.
Dim numbers() As SByte = { SByte.MinValue, -1, 0, 10, SByte.MaxValue }
Dim result As Short

For Each number As SByte In numbers
   result = Convert.ToInt16(number)
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                     number.GetType().Name, number, _
                     result.GetType().Name, result)
Next
' The example displays the following output:
'       Converted the SByte value -128 to the Int16 value -128.
'       Converted the SByte value -1 to the Int16 value -1.
'       Converted the SByte value 0 to the Int16 value 0.
'       Converted the SByte value 10 to the Int16 value 10.
'       Converted the SByte value 127 to the Int16 value 127.

适用于

ToInt16(Int32)

将指定的 32 位有符号整数的值转换为等效的 16 位有符号整数。

public:
 static short ToInt16(int value);
public static short ToInt16 (int value);
static member ToInt16 : int -> int16
Public Shared Function ToInt16 (value As Integer) As Short

参数

value
Int32

要转换的 32 位带符号整数。

返回

Int16

value 等效的 16 位带符号整数。

例外

value 大于 Int16.MaxValue 或小于 Int16.MinValue

示例

以下示例尝试将整数数组中的每个元素转换为 16 位有符号整数。

int[] numbers = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue };
short result;

foreach (int number in numbers)
{
   try {
      result = Convert.ToInt16(number);
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Int32 value -2147483648 is outside the range of the Int16 type.
//    Converted the Int32 value -1 to a Int16 value -1.
//    Converted the Int32 value 0 to a Int16 value 0.
//    Converted the Int32 value 121 to a Int16 value 121.
//    Converted the Int32 value 340 to a Int16 value 340.
//    The Int32 value 2147483647 is outside the range of the Int16 type.
let numbers = 
    [| Int32.MinValue; -1; 0; 121; 340; Int32.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt16 number
        printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int16 type."
// The example displays the following output:
//    The Int32 value -2147483648 is outside the range of the Int16 type.
//    Converted the Int32 value -1 to a Int16 value -1.
//    Converted the Int32 value 0 to a Int16 value 0.
//    Converted the Int32 value 121 to a Int16 value 121.
//    Converted the Int32 value 340 to a Int16 value 340.
//    The Int32 value 2147483647 is outside the range of the Int16 type.
Dim numbers() As Integer = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue }
Dim result As Short

For Each number As Integer In numbers
   Try
      result = Convert.ToInt16(number)
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int32 value -2147483648 is outside the range of the Int16 type.
'    Converted the Int32 value -1 to a Int16 value -1.
'    Converted the Int32 value 0 to a Int16 value 0.
'    Converted the Int32 value 121 to a Int16 value 121.
'    Converted the Int32 value 340 to a Int16 value 340.
'    The Int32 value 2147483647 is outside the range of the Int16 type.

适用于

ToInt16(Int64)

将指定的 64 位有符号整数的值转换为等效的 16 位有符号整数。

public:
 static short ToInt16(long value);
public static short ToInt16 (long value);
static member ToInt16 : int64 -> int16
Public Shared Function ToInt16 (value As Long) As Short

参数

value
Int64

要转换的 64 位带符号整数。

返回

Int16

一个与 value 等效的 16 位带符号整数。

例外

value 大于 Int16.MaxValue 或小于 Int16.MinValue

示例

以下示例尝试将长整数数组中的每个元素转换为 16 位有符号整数。

long[] numbers = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue };
short result;

foreach (long number in numbers)
{
   try {
      result = Convert.ToInt16(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the Int16 type.
//    Converted the Int64 value -1 to the Int16 value -1.
//    Converted the Int64 value 0 to the Int16 value 0.
//    Converted the Int64 value 121 to the Int16 value 121.
//    Converted the Int64 value 340 to the Int16 value 340.
//    The Int64 value 9223372036854775807 is outside the range of the Int16 type.
let numbers =
    [| Int64.MinValue; -1; 0; 121; 340; Int64.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt16 number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int16 type."
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the Int16 type.
//    Converted the Int64 value -1 to the Int16 value -1.
//    Converted the Int64 value 0 to the Int16 value 0.
//    Converted the Int64 value 121 to the Int16 value 121.
//    Converted the Int64 value 340 to the Int16 value 340.
//    The Int64 value 9223372036854775807 is outside the range of the Int16 type.
Dim numbers() As Long = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue }
Dim result As Short
For Each number As Long In numbers
   Try
      result = Convert.ToInt16(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int64 value -9223372036854775808 is outside the range of the Int16 type.
'    Converted the Int64 value -1 to the Int16 value -1.
'    Converted the Int64 value 0 to the Int16 value 0.
'    Converted the Int64 value 121 to the Int16 value 121.
'    Converted the Int64 value 340 to the Int16 value 340.
'    The Int64 value 9223372036854775807 is outside the range of the Int16 type.

适用于

ToInt16(Int16)

返回指定的 16 位有符号整数;不执行实际的转换。

public:
 static short ToInt16(short value);
public static short ToInt16 (short value);
static member ToInt16 : int16 -> int16
Public Shared Function ToInt16 (value As Short) As Short

参数

value
Int16

要转换的 16 位无符号整数。

返回

Int16

不经更改即返回 value

适用于

ToInt16(Double)

将指定的双精度浮点数的值转换为等效的 16 位带符号整数。

public:
 static short ToInt16(double value);
public static short ToInt16 (double value);
static member ToInt16 : double -> int16
Public Shared Function ToInt16 (value As Double) As Short

参数

value
Double

要转换的双精度浮点数。

返回

Int16

value,舍入为最接近的 16 位带符号整数。 如果 value 为两个整数中间的数字,则返回二者中的偶数;即 4.5 转换为 4,而 5.5 转换为 6。

例外

value 大于 Int16.MaxValue 或小于 Int16.MinValue

示例

以下示例将值数组 Double 中的每个元素转换为 16 位有符号整数。 该示例演示在执行转换之前,值的任何小数部分 Double 都舍入。

double[] values = { Double.MinValue, -1.38e10, -1023.299, -12.98,
                    0, 9.113e-16, 103.919, 17834.191, Double.MaxValue };
short result;

foreach (double value in values)
{
   try {
      result = Convert.ToInt16(value);
      Console.WriteLine("Converted {0} to {1}.", value, result);
   }
   catch (OverflowException)
   {
      Console.WriteLine("{0} is outside the range of the Int16 type.", value);
   }
}
//       -1.79769313486232E+308 is outside the range of the Int16 type.
//       -13800000000 is outside the range of the Int16 type.
//       Converted -1023.299 to -1023.
//       Converted -12.98 to -13.
//       Converted 0 to 0.
//       Converted 9.113E-16 to 0.
//       Converted 103.919 to 104.
//       Converted 17834.191 to 17834.
//       1.79769313486232E+308 is outside the range of the Int16 type.
let values =
    [| Double.MinValue; -1.38e10; -1023.299; -12.98
       0; 9.113e-16; 103.919; 17834.191; Double.MaxValue |]

for value in values do
    try
        let result = Convert.ToInt16 value
        printfn $"Converted {value} to {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the Int16 type."
//       -1.79769313486232E+308 is outside the range of the Int16 type.
//       -13800000000 is outside the range of the Int16 type.
//       Converted -1023.299 to -1023.
//       Converted -12.98 to -13.
//       Converted 0 to 0.
//       Converted 9.113E-16 to 0.
//       Converted 103.919 to 104.
//       Converted 17834.191 to 17834.
//       1.79769313486232E+308 is outside the range of the Int16 type.
Dim values() As Double = { Double.MinValue, -1.38e10, -1023.299, -12.98, _
                           0, 9.113e-16, 103.919, 17834.191, Double.MaxValue }
Dim result As Short

For Each value As Double In values
   Try
      result = Convert.ToInt16(value)
      Console.WriteLine("Converted {0} to {1}.", value, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int16 type.", value)
   End Try
Next
'       -1.79769313486232E+308 is outside the range of the Int16 type.
'       -13800000000 is outside the range of the Int16 type.
'       Converted -1023.299 to -1023.
'       Converted -12.98 to -13.
'       Converted 0 to 0.
'       Converted 9.113E-16 to 0.
'       Converted 103.919 to 104.
'       Converted 17834.191 to 17834.
'       1.79769313486232E+308 is outside the range of the Int16 type.

另请参阅

适用于

ToInt16(Decimal)

将指定的十进制数的值转换为等效的 16 位带符号整数。

public:
 static short ToInt16(System::Decimal value);
public static short ToInt16 (decimal value);
static member ToInt16 : decimal -> int16
Public Shared Function ToInt16 (value As Decimal) As Short

参数

value
Decimal

要转换的十进制数。

返回

Int16

value,舍入为最接近的 16 位带符号整数。 如果 value 为两个整数中间的数字,则返回二者中的偶数;即 4.5 转换为 4,而 5.5 转换为 6。

例外

value 大于 Int16.MaxValue 或小于 Int16.MinValue

示例

以下示例尝试将值数组 Decimal 中的每个元素转换为 16 位有符号整数。 该示例演示在执行转换时,值的任何小数部分 Decimal 都舍入。

decimal[] values = { Decimal.MinValue, -1034.23m, -12m, 0m, 147m,
                            9214.16m, Decimal.MaxValue };
short result;

foreach (decimal value in values)
{
   try {
      result = Convert.ToInt16(value);
      Console.WriteLine("Converted {0} to {1}.", value, result);
   }
   catch (OverflowException)
   {
      Console.WriteLine("{0} is outside the range of the Int16 type.",
                        value);
   }
}
// The example displays the following output:
//    -79228162514264337593543950335 is outside the range of the Int16 type.
//    Converted -1034.23 to -1034.
//    Converted -12 to -12.
//    Converted 0 to 0.
//    Converted 147 to 147.
//    Converted 9214.16 to 9214.
//    79228162514264337593543950335 is outside the range of the Int16 type.
let values = 
    [| Decimal.MinValue; -1034.23m; -12m; 0m
       147m; 9214.16m; Decimal.MaxValue |]

for value in values do
    try
        let result = Convert.ToInt16 value
        printfn $"Converted {value} to {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the Int16 type."
// The example displays the following output:
//    -79228162514264337593543950335 is outside the range of the Int16 type.
//    Converted -1034.23 to -1034.
//    Converted -12 to -12.
//    Converted 0 to 0.
//    Converted 147 to 147.
//    Converted 9214.16 to 9214.
//    79228162514264337593543950335 is outside the range of the Int16 type.
Dim values() As Decimal = { Decimal.MinValue, -1034.23d, -12d, 0d, 147d, _
                            9214.16d, Decimal.MaxValue }
Dim result As Short

For Each value As Decimal In values
   Try
      result = Convert.ToInt16(value)
      Console.WriteLine("Converted {0} to {1}.", value, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int16 type.", _
                        value)
   End Try
Next
' The example displays the following output:
'    -79228162514264337593543950335 is outside the range of the Int16 type.
'    Converted -1034.23 to -1034.
'    Converted -12 to -12.
'    Converted 0 to 0.
'    Converted 147 to 147.
'    Converted 9214.16 to 9214.
'    79228162514264337593543950335 is outside the range of the Int16 type.

另请参阅

适用于

ToInt16(DateTime)

调用此方法始终引发 InvalidCastException

public:
 static short ToInt16(DateTime value);
public static short ToInt16 (DateTime value);
static member ToInt16 : DateTime -> int16
Public Shared Function ToInt16 (value As DateTime) As Short

参数

value
DateTime

要转换的日期和时间值。

返回

Int16

不支持此转换。 不返回任何值。

例外

不支持此转换。

适用于

ToInt16(Char)

将指定的 Unicode 字符的值转换为等效的 16 位有符号整数。

public:
 static short ToInt16(char value);
public static short ToInt16 (char value);
static member ToInt16 : char -> int16
Public Shared Function ToInt16 (value As Char) As Short

参数

value
Char

要转换的 Unicode 字符。

返回

Int16

一个与 value 等效的 16 位带符号整数。

例外

示例

以下示例尝试将值数组 Char 中的每个元素转换为 16 位有符号整数。

char[] chars = { 'a', 'z', '\x0007', '\x03FF',
                 '\x7FFF', '\xFFFE' };
short result;

foreach (char ch in chars)
{
   try {
      result = Convert.ToInt16(ch);
      Console.WriteLine("'{0}' converts to {1}.", ch, result);
   }
   catch (OverflowException) {
      Console.WriteLine("Unable to convert u+{0} to an Int16.",
                        ((int)ch).ToString("X4"));
   }
}
// The example displays the following output:
//       'a' converts to 97.
//       'z' converts to 122.
//       '' converts to 7.
//       'Ͽ' converts to 1023.
//       '翿' converts to 32767.
//       Unable to convert u+FFFE to an Int16.
let chars = 
    [| 'a'; 'z'; '\u0007'; '\u03FF'; '\u7FFF'; '\uFFFE' |]

for ch in chars do
    try
        let result = Convert.ToInt16 ch
        printfn $"'{ch}' converts to {result}."
    with :? OverflowException ->
        printfn $"Unable to convert u+{int ch:X4} to an Int16."
// The example displays the following output:
//       'a' converts to 97.
//       'z' converts to 122.
//       '' converts to 7.
//       'Ͽ' converts to 1023.
//       '翿' converts to 32767.
//       Unable to convert u+FFFE to an Int16.
Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(1023), _
                        ChrW(Short.MaxValue), ChrW(&hFFFE) }
Dim result As Short

For Each ch As Char in chars
   Try
      result = Convert.ToInt16(ch)
      Console.WriteLine("'{0}' converts to {1}.", ch, result)
   Catch e As OverflowException
      Console.WriteLine("Unable to convert u+{0} to an Int16.", _
                        AscW(ch).ToString("X4"))
   End Try
Next
' The example displays the following output:
'       'a' converts to 97.
'       'z' converts to 122.
'       '' converts to 7.
'       'Ͽ' converts to 1023.
'       '翿' converts to 32767.
'       Unable to convert u+FFFE to an Int16.

适用于

ToInt16(Byte)

将指定的 8 位无符号整数的值转换为等效的 16 位有符号整数。

public:
 static short ToInt16(System::Byte value);
public static short ToInt16 (byte value);
static member ToInt16 : byte -> int16
Public Shared Function ToInt16 (value As Byte) As Short

参数

value
Byte

要转换的 8 位无符号整数。

返回

Int16

一个与 value 等效的 16 位带符号整数。

示例

以下示例将值数组 Byte 中的每个元素转换为 16 位有符号整数。

byte[] bytes = { Byte.MinValue, 14, 122, Byte.MaxValue};
short result;

foreach (byte byteValue in bytes)
{
   result = Convert.ToInt16(byteValue);
   Console.WriteLine("The Byte value {0} converts to {1}.",
                     byteValue, result);
}
// The example displays the following output:
//       The Byte value 0 converts to 0.
//       The Byte value 14 converts to 14.
//       The Byte value 122 converts to 122.
//       The Byte value 255 converts to 255.
let bytes = [| Byte.MinValue; 14uy; 122uy; Byte.MaxValue |]

for byteValue in bytes do
    let result = Convert.ToInt16 byteValue
    printfn $"The Byte value {byteValue} converts to {result}."
// The example displays the following output:
//       The Byte value 0 converts to 0.
//       The Byte value 14 converts to 14.
//       The Byte value 122 converts to 122.
//       The Byte value 255 converts to 255.
Dim bytes() As Byte = { Byte.MinValue, 14, 122, Byte.MaxValue}
Dim result As Short

For Each byteValue As Byte In bytes
   result = Convert.ToInt16(byteValue)
   Console.WriteLine("The Byte value {0} converts to {1}.", _
                     byteValue, result)
Next
' The example displays the following output:
'       The Byte value 0 converts to 0.
'       The Byte value 14 converts to 14.
'       The Byte value 122 converts to 122.
'       The Byte value 255 converts to 255.

适用于

ToInt16(Boolean)

将指定的布尔值转换为等效的 16 位带符号整数。

public:
 static short ToInt16(bool value);
public static short ToInt16 (bool value);
static member ToInt16 : bool -> int16
Public Shared Function ToInt16 (value As Boolean) As Short

参数

value
Boolean

要转换的布尔值。

返回

Int16

如果 valuetrue,则为数字 1;否则,为 0。

示例

以下示例将布尔值 truefalse 值转换为 Int16 值。

bool falseFlag = false;
bool trueFlag = true;

Console.WriteLine("{0} converts to {1}.", falseFlag,
                  Convert.ToInt16(falseFlag));
Console.WriteLine("{0} converts to {1}.", trueFlag,
                  Convert.ToInt16(trueFlag));
// The example displays the following output:
//       False converts to 0.
//       True converts to 1.
let falseFlag = false
let trueFlag = true

printfn $"{falseFlag} converts to {Convert.ToInt16 falseFlag}."
printfn $"{trueFlag} converts to {Convert.ToInt16 trueFlag}."
// The example displays the following output:
//       False converts to 0.
//       True converts to 1.
Dim falseFlag As Boolean = False
Dim trueFlag As Boolean = True

Console.WriteLine("{0} converts to {1}.", falseFlag, _
                  Convert.ToInt16(falseFlag))
Console.WriteLine("{0} converts to {1}.", trueFlag, _
                  Convert.ToInt16(trueFlag))
' The example displays the following output:
'       False converts to 0.
'       True converts to 1.

适用于

ToInt16(Object)

将指定对象的值转换为 16 位带符号整数。

public:
 static short ToInt16(System::Object ^ value);
public static short ToInt16 (object value);
public static short ToInt16 (object? value);
static member ToInt16 : obj -> int16
Public Shared Function ToInt16 (value As Object) As Short

参数

value
Object

用于实现 IConvertible 接口的对象,或为 null

返回

Int16

一个与 value 等效的 16 位带符号整数,如果 valuenull,则为零。

例外

对于 Int16 类型,value 的格式不正确。

value 不实现 IConvertible 接口。

  • 或 -

不支持该转换。

value 表示小于 Int16.MinValue 或大于 Int16.MaxValue 的数字。

示例

以下示例尝试将对象数组中的每个元素转换为 16 位有符号整数。

object[] values= { true, -12, 163, 935, 'x', new DateTime(2009, 5, 12),
                   "104", "103.0", "-1", "1.00e2", "One", 1.00e2};
short result;

foreach (object value in values)
{
   try {
      result = Convert.ToInt16(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.",
                        value.GetType().Name, value);
   }
   catch (FormatException) {
      Console.WriteLine("The {0} value {1} is not in a recognizable format.",
                        value.GetType().Name, value);
   }
   catch (InvalidCastException) {
      Console.WriteLine("No conversion to an Int16 exists for the {0} value {1}.",
                        value.GetType().Name, value);
   }
}
// The example displays the following output:
//    Converted the Boolean value True to the Int16 value 1.
//    Converted the Int32 value -12 to the Int16 value -12.
//    Converted the Int32 value 163 to the Int16 value 163.
//    Converted the Int32 value 935 to the Int16 value 935.
//    Converted the Char value x to the Int16 value 120.
//    No conversion to an Int16 exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the Int16 value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the Int16 value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the Int16 value 100.
let values: obj[] =
    [| true; -12; 163; 935; 'x'; DateTime(2009, 5, 12)
       "104"; "103.0"; "-1"; "1.00e2"; "One"; 1.00e2 |]

for value in values do
    try
        let result = Convert.ToInt16 value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with 
    | :? OverflowException ->
        printfn $"The {value.GetType().Name} value {value} is outside the range of the Int16 type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value {value} is not in a recognizable format."
    | :? InvalidCastException ->
        printfn $"No conversion to an Int16 exists for the {value.GetType().Name} value {value}."
// The example displays the following output:
//    Converted the Boolean value True to the Int16 value 1.
//    Converted the Int32 value -12 to the Int16 value -12.
//    Converted the Int32 value 163 to the Int16 value 163.
//    Converted the Int32 value 935 to the Int16 value 935.
//    Converted the Char value x to the Int16 value 120.
//    No conversion to an Int16 exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the Int16 value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the Int16 value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the Int16 value 100.
Dim values() As Object = { True, -12, 163, 935, "x"c, #5/12/2009#, _
                           "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2}
Dim result As Short

For Each value As Object In values
   Try
      result = Convert.ToInt16(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int16 type.", _
                        value.GetType().Name, value)
   Catch e As FormatException
      Console.WriteLine("The {0} value {1} is not in a recognizable format.", _
                        value.GetType().Name, value)
   Catch e As InvalidCastException
      Console.WriteLine("No conversion to an Int16 exists for the {0} value {1}.", _
                        value.GetType().Name, value)

   End Try
Next
' The example displays the following output:
'    Converted the Boolean value True to the Int16 value 1.
'    Converted the Int32 value -12 to the Int16 value -12.
'    Converted the Int32 value 163 to the Int16 value 163.
'    Converted the Int32 value 935 to the Int16 value 935.
'    Converted the Char value x to the Int16 value 120.
'    No conversion to an Int16 exists for the DateTime value 5/12/2009 12:00:00 AM.
'    Converted the String value 104 to the Int16 value 104.
'    The String value 103.0 is not in a recognizable format.
'    Converted the String value -1 to the Int16 value -1.
'    The String value 1.00e2 is not in a recognizable format.
'    The String value One is not in a recognizable format.
'    Converted the Double value 100 to the Int16 value 100.

注解

null否则value,此方法包装对IConvertible.ToInt16基础类型的value实现的调用。

适用于