Convert.ToSByte 方法

定义

将指定的值转换为 8 位有符号整数。

重载

ToSByte(UInt32)

将指定的 32 位无符号整数的值转换为等效的 8 位有符号整数。

ToSByte(String)

将数字的指定字符串表示形式转换为等效的 8 位带符号整数。

ToSByte(UInt64)

将指定的 64 位无符号整数的值转换为等效的 8 位有符号整数。

ToSByte(UInt16)

将指定的 16 位无符号整数的值转换为等效的 8 位有符号整数。

ToSByte(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 8 位带符号整数。

ToSByte(String, Int32)

将指定基数的数字的字符串表示形式转换为等效的 8 位有符号整数。

ToSByte(Single)

将指定的单精度浮点数的值转换为等效的 8 位带符号整数。

ToSByte(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 8 位带符号整数。

ToSByte(SByte)

返回指定的 8 位有符号整数;不执行实际的转换。

ToSByte(Int32)

将指定的 32 位有符号整数的值转换为等效的 8 位有符号整数。

ToSByte(Int64)

将指定的 64 位有符号整数的值转换为等效的 8 位有符号整数。

ToSByte(Object)

将指定对象的值转换为 8 位带符号整数。

ToSByte(Byte)

将指定的 8 位无符号整数的值转换为等效的 8 位有符号整数。

ToSByte(Char)

将指定的 Unicode 字符的值转换为等效的 8 位有符号整数。

ToSByte(DateTime)

调用此方法始终引发 InvalidCastException

ToSByte(Boolean)

将指定的布尔值转换为等效的 8 位带符号整数。

ToSByte(Double)

将指定的双精度浮点数的值转换为等效的 8 位带符号整数。

ToSByte(Int16)

将指定的 16 位带符号整数的值转换为等效的 8 位带符号整数。

ToSByte(Decimal)

将指定的十进制数的值转换为等效的 8 位带符号整数。

ToSByte(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 8 位有符号整数。

public:
 static System::SByte ToSByte(System::UInt32 value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (uint value);
[<System.CLSCompliant(false)>]
static member ToSByte : uint32 -> sbyte
Public Shared Function ToSByte (value As UInteger) As SByte

参数

value
UInt32

要转换的 32 位无符号整数。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将整数数组中的每个元素转换为带符号字节。

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

foreach (uint number in numbers)
{
   try {
      result = Convert.ToSByte(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 SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt32 value 0 to the SByte value 0.
//    Converted the UInt32 value 121 to the SByte value 121.
//    The UInt32 value 340 is outside the range of the SByte type.
//    The UInt32 value 4294967295 is outside the range of the SByte type.
let numbers =
    [| UInt16.MinValue; 121us; 340us; UInt16.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToSByte 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 SByte type."
// The example displays the following output:
//    Converted the UInt16 value 0 to the SByte value 0.
//    Converted the UInt16 value 121 to the SByte value 121.
//    Converted the UInt16 value 340 to the SByte value 340.
//    Converted the UInt16 value 65535 to the SByte value 65535.
Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As SByte
For Each number As UInteger In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt32 value 0 to the SByte value 0.
'    Converted the UInt32 value 121 to the SByte value 121.
'    The UInt32 value 340 is outside the range of the SByte type.
'    The UInt32 value 4294967295 is outside the range of the SByte type.

适用于

ToSByte(String)

重要

此 API 不符合 CLS。

将数字的指定字符串表示形式转换为等效的 8 位带符号整数。

public:
 static System::SByte ToSByte(System::String ^ value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string? value);
[<System.CLSCompliant(false)>]
static member ToSByte : string -> sbyte
Public Shared Function ToSByte (value As String) As SByte

参数

value
String

包含要转换的数字的字符串。

返回

SByte

value 中数字等效的 8 位带符号整数,如果值为 null,则为 0(零)。

属性

例外

value 不由一个可选符号后跟一系列数字 (0-9) 组成。

value 表示一个小于 MinValue 或大于 MaxValue 的数字。

示例

以下示例使用默认格式将值的字符串表示形式 SByte 与方法一起 ToSByte 转换。

// Example of the Convert::ToSByte( String* ) and 
// Convert::ToSByte( 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 ConvertToSByte( String^ numericStr, IFormatProvider^ provider )
{
   Object^ defaultValue;
   Object^ providerValue;
   
   // Convert numericStr to SByte without a format provider.
   try
   {
      defaultValue = Convert::ToSByte( numericStr );
   }
   catch ( Exception^ ex ) 
   {
      defaultValue = GetExceptionType( ex );
   }

   
   // Convert numericStr to SByte with a format provider.
   try
   {
      providerValue = Convert::ToSByte( 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->NumberNegativePattern = 0;
   Console::WriteLine( "This example of\n"
   "  Convert::ToSByte( String* ) and \n"
   "  Convert::ToSByte( String*, IFormatProvider* ) "
   "\ngenerates the following output. It converts "
   "several strings to \nSByte 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.
   ConvertToSByte( "123", provider );
   ConvertToSByte( "+123", provider );
   ConvertToSByte( "pos 123", provider );
   ConvertToSByte( "-123", provider );
   ConvertToSByte( "neg 123", provider );
   ConvertToSByte( "123.", provider );
   ConvertToSByte( "(123)", provider );
   ConvertToSByte( "128", provider );
   ConvertToSByte( "-129", provider );
}

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

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( string, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToSByteProviderDemo
{
    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 ConvertToSByte( string numericStr,
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

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

        // Convert numericStr to SByte with a format provider.
        try
        {
            providerValue = Convert.ToSByte( 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.NumberNegativePattern = 0;

        Console.WriteLine("This example of\n" +
            "  Convert.ToSByte( string ) and \n" +
            "  Convert.ToSByte( string, IFormatProvider ) " +
            "\ngenerates the following output. It converts " +
            "several strings to \nSByte 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.
        ConvertToSByte( "123", provider );
        ConvertToSByte( "+123", provider );
        ConvertToSByte( "pos 123", provider );
        ConvertToSByte( "-123", provider );
        ConvertToSByte( "neg 123", provider );
        ConvertToSByte( "123.", provider );
        ConvertToSByte( "(123)", provider );
        ConvertToSByte( "128", provider );
        ConvertToSByte( "-129", provider );
    }
}

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

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( 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 convertToSByte (numericStr: string) (provider: IFormatProvider) =
    // Convert numericStr to SByte without a format provider.
    let defaultValue =
        try
            Convert.ToSByte numericStr
            |> string
        with ex -> 
            getExceptionType ex

    // Convert numericStr to SByte with a format provider.
    let providerValue = 
        try
            Convert.ToSByte(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.NumberNegativePattern <- 0

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

// Convert strings, with and without an IFormatProvider.
convertToSByte "123" provider
convertToSByte "+123" provider
convertToSByte "pos 123" provider
convertToSByte "-123" provider 
convertToSByte "neg 123" provider 
convertToSByte "123." provider 
convertToSByte "(123)" provider 
convertToSByte "128" provider 
convertToSByte "-129" provider 


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

// String to convert   Default/exception   Provider/exception
// -----------------   -----------------   ------------------
// 123                 123                 123
// +123                123                 FormatException
// pos 123             FormatException     123
// -123                -123                FormatException
// neg 123             FormatException     -123
// 123.                FormatException     FormatException
// (123)               FormatException     FormatException
// 128                 OverflowException   OverflowException
// -129                OverflowException   FormatException
' Example of the Convert.ToSByte( String ) and 
' Convert.ToSByte( String, IFormatProvider ) methods.
Imports System.Globalization

Module ToSByteProviderDemo

    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 ConvertToSByte( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

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

        ' Convert numericStr to SByte with a format provider.
        Try
            providerValue = Convert.ToSByte( 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.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToSByte( String ) and " & vbCrLf & _
            "  Convert.ToSByte( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "SByte " & _
            "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.
        ConvertToSByte( "123", provider )
        ConvertToSByte( "+123", provider )
        ConvertToSByte( "pos 123", provider )
        ConvertToSByte( "-123", provider )
        ConvertToSByte( "neg 123", provider )
        ConvertToSByte( "123.", provider )
        ConvertToSByte( "(123)", provider )
        ConvertToSByte( "128", provider )
        ConvertToSByte( "-129", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToSByte( String ) and
'   Convert.ToSByte( String, IFormatProvider )
' generates the following output. It converts several strings to
' SByte values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 123                 123                 123
' +123                123                 FormatException
' pos 123             FormatException     123
' -123                -123                FormatException
' neg 123             FormatException     -123
' 123.                FormatException     FormatException
' (123)               FormatException     FormatException
' 128                 OverflowException   OverflowException
' -129                OverflowException   FormatException

注解

使用该方法ToSByte(String)等效于传递给valueSByte.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 SByte.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

ToSByte(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 8 位有符号整数。

public:
 static System::SByte ToSByte(System::UInt64 value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (ulong value);
[<System.CLSCompliant(false)>]
static member ToSByte : uint64 -> sbyte
Public Shared Function ToSByte (value As ULong) As SByte

参数

value
UInt64

要转换的 64 位无符号整数。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将长整数数组中的每个元素转换为带符号字节。

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

foreach (ulong number in numbers)
{
   try {
      result = Convert.ToSByte(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 SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt64 value 0 to the SByte value 0.
//    Converted the UInt64 value 121 to the SByte value 121.
//    The UInt64 value 340 is outside the range of the SByte type.
//    The UInt64 value 18446744073709551615 is outside the range of the SByte type.
let numbers =
    [| UInt32.MinValue; 121u; 340u; UInt32.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToSByte 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 SByte type."
// The example displays the following output:
//    Converted the UInt32 value 0 to the SByte value 0.
//    Converted the UInt32 value 121 to the SByte value 121.
//    Converted the UInt32 value 340 to the SByte value 340.
//    The UInt32 value 4294967295 is outside the range of the SByte type.
Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As SByte
For Each number As ULong In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt64 value 0 to the SByte value 0.
'    Converted the UInt64 value 121 to the SByte value 121.
'    The UInt64 value 340 is outside the range of the SByte type.
'    The UInt64 value 18446744073709551615 is outside the range of the SByte type.

适用于

ToSByte(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 8 位有符号整数。

public:
 static System::SByte ToSByte(System::UInt16 value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (ushort value);
[<System.CLSCompliant(false)>]
static member ToSByte : uint16 -> sbyte
Public Shared Function ToSByte (value As UShort) As SByte

参数

value
UInt16

要转换的 16 位无符号整数。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue

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有符号字节。

ushort[] numbers = { UInt16.MinValue, 121, 340, UInt16.MaxValue };
sbyte result;

foreach (ushort number in numbers)
{
   try {
      result = Convert.ToSByte(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 SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt16 value 0 to the SByte value 0.
//    Converted the UInt16 value 121 to the SByte value 121.
//    The UInt16 value 340 is outside the range of the SByte type.
//    The UInt16 value 65535 is outside the range of the SByte type.
let values = 
    [| "One"; "1.34e28"; "-26.87"; "-18"; "-6.00"
       " 0"; "137"; "1601.9"; string Int32.MaxValue |]

for value in values do
    try
        let result = Convert.ToSByte 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 SByte type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value '{value}' is not in a recognizable format."
// The example displays the following output:
//    The String value 'One' is not in a recognizable format.
//    The String value '1.34e28' is not in a recognizable format.
//    The String value '-26.87' is not in a recognizable format.
//    Converted the String value '-18' to the SByte value -18.
//    The String value '-6.00' is not in a recognizable format.
//    Converted the String value ' 0' to the SByte value 0.
//    Converted the String value '137' to the SByte value 137.
//    The String value '1601.9' is not in a recognizable format.
//    Converted the String value '2147483647' to the SByte value 2147483647.
Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As SByte
For Each number As UShort In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt16 value 0 to the SByte value 0.
'    Converted the UInt16 value 121 to the SByte value 121.
'    The UInt16 value 340 is outside the range of the SByte type.
'    The UInt16 value 65535 is outside the range of the SByte type.

适用于

ToSByte(String, IFormatProvider)

重要

此 API 不符合 CLS。

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 8 位带符号整数。

public:
 static System::SByte ToSByte(System::String ^ value, IFormatProvider ^ provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value, IFormatProvider provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value, IFormatProvider? provider);
[<System.CLSCompliant(false)>]
static member ToSByte : string * IFormatProvider -> sbyte
Public Shared Function ToSByte (value As String, provider As IFormatProvider) As SByte

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

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 上声明的默认值为 null

value 不由一个可选符号后跟一系列数字 (0-9) 组成。

value 表示一个小于 MinValue 或大于 MaxValue 的数字。

示例

以下示例使用IFormatProvider对象使用ToSByte方法转换值的字符串表示形式SByte

// Example of the Convert::ToSByte( String* ) and 
// Convert::ToSByte( 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 ConvertToSByte( String^ numericStr, IFormatProvider^ provider )
{
   Object^ defaultValue;
   Object^ providerValue;
   
   // Convert numericStr to SByte without a format provider.
   try
   {
      defaultValue = Convert::ToSByte( numericStr );
   }
   catch ( Exception^ ex ) 
   {
      defaultValue = GetExceptionType( ex );
   }

   
   // Convert numericStr to SByte with a format provider.
   try
   {
      providerValue = Convert::ToSByte( 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->NumberNegativePattern = 0;
   Console::WriteLine( "This example of\n"
   "  Convert::ToSByte( String* ) and \n"
   "  Convert::ToSByte( String*, IFormatProvider* ) "
   "\ngenerates the following output. It converts "
   "several strings to \nSByte 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.
   ConvertToSByte( "123", provider );
   ConvertToSByte( "+123", provider );
   ConvertToSByte( "pos 123", provider );
   ConvertToSByte( "-123", provider );
   ConvertToSByte( "neg 123", provider );
   ConvertToSByte( "123.", provider );
   ConvertToSByte( "(123)", provider );
   ConvertToSByte( "128", provider );
   ConvertToSByte( "-129", provider );
}

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

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( string, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToSByteProviderDemo
{
    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 ConvertToSByte( string numericStr,
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

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

        // Convert numericStr to SByte with a format provider.
        try
        {
            providerValue = Convert.ToSByte( 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.NumberNegativePattern = 0;

        Console.WriteLine("This example of\n" +
            "  Convert.ToSByte( string ) and \n" +
            "  Convert.ToSByte( string, IFormatProvider ) " +
            "\ngenerates the following output. It converts " +
            "several strings to \nSByte 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.
        ConvertToSByte( "123", provider );
        ConvertToSByte( "+123", provider );
        ConvertToSByte( "pos 123", provider );
        ConvertToSByte( "-123", provider );
        ConvertToSByte( "neg 123", provider );
        ConvertToSByte( "123.", provider );
        ConvertToSByte( "(123)", provider );
        ConvertToSByte( "128", provider );
        ConvertToSByte( "-129", provider );
    }
}

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

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( 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 convertToSByte (numericStr: string) (provider: IFormatProvider) =
    // Convert numericStr to SByte without a format provider.
    let defaultValue =
        try
            Convert.ToSByte numericStr
            |> string
        with ex -> 
            getExceptionType ex

    // Convert numericStr to SByte with a format provider.
    let providerValue = 
        try
            Convert.ToSByte(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.NumberNegativePattern <- 0

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

// Convert strings, with and without an IFormatProvider.
convertToSByte "123" provider
convertToSByte "+123" provider
convertToSByte "pos 123" provider
convertToSByte "-123" provider 
convertToSByte "neg 123" provider 
convertToSByte "123." provider 
convertToSByte "(123)" provider 
convertToSByte "128" provider 
convertToSByte "-129" provider 


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

// String to convert   Default/exception   Provider/exception
// -----------------   -----------------   ------------------
// 123                 123                 123
// +123                123                 FormatException
// pos 123             FormatException     123
// -123                -123                FormatException
// neg 123             FormatException     -123
// 123.                FormatException     FormatException
// (123)               FormatException     FormatException
// 128                 OverflowException   OverflowException
// -129                OverflowException   FormatException
' Example of the Convert.ToSByte( String ) and 
' Convert.ToSByte( String, IFormatProvider ) methods.
Imports System.Globalization

Module ToSByteProviderDemo

    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 ConvertToSByte( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

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

        ' Convert numericStr to SByte with a format provider.
        Try
            providerValue = Convert.ToSByte( 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.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToSByte( String ) and " & vbCrLf & _
            "  Convert.ToSByte( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "SByte " & _
            "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.
        ConvertToSByte( "123", provider )
        ConvertToSByte( "+123", provider )
        ConvertToSByte( "pos 123", provider )
        ConvertToSByte( "-123", provider )
        ConvertToSByte( "neg 123", provider )
        ConvertToSByte( "123.", provider )
        ConvertToSByte( "(123)", provider )
        ConvertToSByte( "128", provider )
        ConvertToSByte( "-129", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToSByte( String ) and
'   Convert.ToSByte( String, IFormatProvider )
' generates the following output. It converts several strings to
' SByte values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 123                 123                 123
' +123                123                 FormatException
' pos 123             FormatException     123
' -123                -123                FormatException
' neg 123             FormatException     -123
' 123.                FormatException     FormatException
' (123)               FormatException     FormatException
' 128                 OverflowException   OverflowException
' -129                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 SByte.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

ToSByte(String, Int32)

重要

此 API 不符合 CLS。

将指定基数的数字的字符串表示形式转换为等效的 8 位有符号整数。

public:
 static System::SByte ToSByte(System::String ^ value, int fromBase);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value, int fromBase);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string? value, int fromBase);
[<System.CLSCompliant(false)>]
static member ToSByte : string * int -> sbyte
Public Shared Function ToSByte (value As String, fromBase As Integer) As SByte

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

SByte

value 中数字等效的 8 位带符号整数,如果 valuenull,则为 0(零)。

属性

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 表示一个小于 MinValue 或大于 MaxValue 的数字。

示例

以下示例尝试将字符串数组中的元素解释为数值的二进制、八进制和十六进制表示形式,以便将它们转换为无符号字节。

using System;

public class Example
{
   public static void Main()
   {
      int[] baseValues = { 2, 8, 16};
      string[] values = { "FF", "81", "03", "11", "8F", "01", "1C", "111",
                          "123", "18A" };

      // Convert to each supported base.
      foreach (int baseValue in baseValues)
      {
         Console.WriteLine("Converting strings in base {0}:", baseValue);
         foreach (string value in values)
         {
            Console.Write("   '{0,-5}  -->  ", value + "'");
            try {
               Console.WriteLine(Convert.ToSByte(value, baseValue));
            }
            catch (FormatException) {
               Console.WriteLine("Bad Format");
            }
            catch (OverflowException) {
               Console.WriteLine("Out of Range");
            }
         }
         Console.WriteLine();
      }
   }
}
// The example displays the following output:
//       Converting strings in base 2:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  Bad Format
//          '11'    -->  3
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  7
//          '123'   -->  Bad Format
//          '18A'   -->  Bad Format
//
//       Converting strings in base 8:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  3
//          '11'    -->  9
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  73
//          '123'   -->  83
//          '18A'   -->  Bad Format
//
//       Converting strings in base 16:
//          'FF'    -->  -1
//          '81'    -->  -127
//          '03'    -->  3
//          '11'    -->  17
//          '8F'    -->  -113
//          '01'    -->  1
//          '1C'    -->  28
//          '111'   -->  Out of Range
//          '123'   -->  Out of Range
//          '18A'   -->  Out of Range
open System

let baseValues =
    [| 2; 8; 16 |]
let values =
    [| "FF"; "81"; "03"; "11"; "8F"; "01"; "1C"; "111"; "123"; "18A" |]

// Convert to each supported base.
for baseValue in baseValues do
    printfn $"Converting strings in base {baseValue}:"
    for value in values do
        printf $"""   '{value + "'",-5}  -->  """
        try
            printfn $"{Convert.ToSByte(value, baseValue)}"
        with
        | :? FormatException ->
            printfn "Bad Format"
        | :? OverflowException ->
            printfn "Out of Range"
    printfn ""

// The example displays the following output:
//       Converting strings in base 2:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  Bad Format
//          '11'    -->  3
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  7
//          '123'   -->  Bad Format
//          '18A'   -->  Bad Format
//
//       Converting strings in base 8:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  3
//          '11'    -->  9
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  73
//          '123'   -->  83
//          '18A'   -->  Bad Format
//
//       Converting strings in base 16:
//          'FF'    -->  -1
//          '81'    -->  -127
//          '03'    -->  3
//          '11'    -->  17
//          '8F'    -->  -113
//          '01'    -->  1
//          '1C'    -->  28
//          '111'   -->  Out of Range
//          '123'   -->  Out of Range
//          '18A'   -->  Out of Range
Module Example
   Public Sub Main()
      Dim bases() As Integer = { 2, 8, 16}
      Dim values() As String = { "FF", "81", "03", "11", "8F", "01", "1C", _ 
                                 "111", "123", "18A" } 
   
      ' Convert to each supported base.
      For Each base As Integer In bases
         Console.WriteLine("Converting strings in base {0}:", base)
         For Each value As String In values
            Console.Write("   '{0,-5}  -->  ", value + "'")
            Try
               Console.WriteLine(Convert.ToSByte(value, base))
            Catch e As FormatException
               Console.WriteLine("Bad Format")
            Catch e As OverflowException
               Console.WriteLine("Out of Range")
            End Try   
         Next
         Console.WriteLine()
      Next
   End Sub
End Module
' The example displays the following output:
'       Converting strings in base 2:
'          'FF'    -->  Bad Format
'          '81'    -->  Bad Format
'          '03'    -->  Bad Format
'          '11'    -->  3
'          '8F'    -->  Bad Format
'          '01'    -->  1
'          '1C'    -->  Bad Format
'          '111'   -->  7
'          '123'   -->  Bad Format
'          '18A'   -->  Bad Format
'       
'       Converting strings in base 8:
'          'FF'    -->  Bad Format
'          '81'    -->  Bad Format
'          '03'    -->  3
'          '11'    -->  9
'          '8F'    -->  Bad Format
'          '01'    -->  1
'          '1C'    -->  Bad Format
'          '111'   -->  73
'          '123'   -->  83
'          '18A'   -->  Bad Format
'       
'       Converting strings in base 16:
'          'FF'    -->  -1
'          '81'    -->  -127
'          '03'    -->  3
'          '11'    -->  17
'          '8F'    -->  -113
'          '01'    -->  1
'          '1C'    -->  28
'          '111'   -->  Out of Range
'          '123'   -->  Out of Range
'          '18A'   -->  Out of Range

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 ToSByte(String, Int32) 假定负数使用两个的补数表示形式。 换句话说,该方法始终将字节 (位 7 位) 的高阶位解释为其符号位。 因此,可以编写代码,其中非基 10 数字在数据类型范围 SByte 之外转换为 SByte 值而不引发异常的方法。 下面的示例转换为 MaxValue 其十六进制字符串表示形式,然后调用该方法 ToSByte(String, Int32) 。 该方法不引发异常,而是显示消息“0xff转换为 -1”。

// Create a hexadecimal value out of range of the SByte type.
string value = Convert.ToString(byte.MaxValue, 16);
// Convert it back to a number.
try
{
   sbyte number = Convert.ToSByte(value, 16);
   Console.WriteLine("0x{0} converts to {1}.", value, number);
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a signed byte.", value);
}
// Create a hexadecimal value out of range of the SByte type.
let value = Convert.ToString(Byte.MaxValue, 16)
// Convert it back to a number.
try
    let number = Convert.ToSByte(value, 16)
    printfn $"0x{value} converts to {number}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to a signed byte."
' Create a hexadecimal value out of range of the SByte type.
Dim value As String = Convert.ToString(Byte.MaxValue, 16)
' Convert it back to a number.
Try
   Dim number As SByte = Convert.ToSByte(value, 16)
   Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a signed byte.", 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,在将值转换为其十六进制字符串表示形式时,首先确定值是否表示无符号类型或有符号类型,以确保该方法处理溢出。 如果原始值是无符号类型,但转换回签名字节会生成一个登录位的值,则引发异常。

// Create a hexadecimal value out of range of the SByte type.
byte sourceNumber = byte.MaxValue;
bool isSigned = Math.Sign(Convert.ToDouble(sourceNumber.GetType().GetField("MinValue").GetValue(null))) == -1;
string value = Convert.ToString(sourceNumber, 16);
sbyte targetNumber;
try
{
   targetNumber = Convert.ToSByte(value, 16);
   if (! isSigned && ((targetNumber & 0x80) != 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 signed byte.", value);
}
// Displays the following to the console:
//    Unable to convert '0xff' to a signed byte.
// Create a hexadecimal value out of range of the SByte type.
let sourceNumber = Byte.MaxValue
let isSigned = sign (Convert.ToDouble(sourceNumber.GetType().GetField("MinValue").GetValue null)) = -1
let value = Convert.ToString(sourceNumber, 16)
try
    let targetNumber = Convert.ToSByte(value, 16)
    if not isSigned && targetNumber &&& 0x80y <> 0y then
        raise (OverflowException())
    else
    printfn $"0x{value} converts to {targetNumber}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to a signed byte."
// Displays the following to the console:
//    Unable to convert '0xff' to a signed byte.
' Create a negative hexadecimal value out of range of the Long type.
Dim sourceNumber As Byte = Byte.MaxValue
Dim isSigned As Boolean = Math.Sign(sourceNumber.MinValue) = -1
Dim value As String = Convert.ToString(sourceNumber, 16)
Dim targetNumber As SByte
Try
   targetNumber = Convert.ToSByte(value, 16)
   If Not isSigned And ((targetNumber And &H80) <> 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 signed byte.", value)
End Try 
' Displays the following to the console:
'    Unable to convert '0xff' to a signed byte.

适用于

ToSByte(Single)

重要

此 API 不符合 CLS。

将指定的单精度浮点数的值转换为等效的 8 位带符号整数。

public:
 static System::SByte ToSByte(float value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (float value);
[<System.CLSCompliant(false)>]
static member ToSByte : single -> sbyte
Public Shared Function ToSByte (value As Single) As SByte

参数

value
Single

要转换的单精度浮点数。

返回

SByte

value,舍入为最接近的 8 位有符号整数。 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。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将值数组 Single 中的每个元素转换为带符号字节。

object[] values = { true, -12, 163, 935, 'x', "104", "103.0", "-1",
                    "1.00e2", "One", 1.00e2};
sbyte result;

foreach (object value in values)
{
   try {
      result = Convert.ToSByte(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 SByte 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 a Byte exists for the {0} value {1}.",
                        value.GetType().Name, value);
   }
}
// The example displays the following output:
//    Converted the Boolean value true to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    The Int32 value 163 is outside the range of the SByte type.
//    The Int32 value 935 is outside the range of the SByte type.
//    Converted the Char value x to the SByte value 120.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte 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 SByte value 100.
let values: obj[] = 
    [| true; -12; 163; 935; 'x'; DateTime(2009, 5, 12)
       "104"; "103.0"; "-1"
       "1.00e2"; "One"; 1.00e2; 16.3e42 |]

for value in values do
    try
        let result = Convert.ToSByte 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 SByte type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value {value} is not in a recognizable format."
    | :? InvalidCastException ->
        printfn $"No conversion to an SByte exists for the {value.GetType().Name} value {value}."
// The example displays the following output:
//    Converted the Boolean value True to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    Converted the Int32 value 163 to the SByte value 163.
//    Converted the Int32 value 935 to the SByte value 935.
//    Converted the Char value x to the SByte value 120.
//    No conversion to an SByte exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte 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 SByte value 100.
//    The Double value 1.63E+43 is outside the range of the SByte type.
Dim values() As Object = { True, -12, 163, 935, "x"c, "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2}
Dim result As SByte
For Each value As Object In values
   Try
      result = Convert.ToSByte(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 SByte 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 a Byte 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 SByte value 1.
'    Converted the Int32 value -12 to the SByte value -12.
'    The Int32 value 163 is outside the range of the SByte type.
'    The Int32 value 935 is outside the range of the SByte type.
'    Converted the Char value x to the SByte value 120.
'    Converted the String value 104 to the SByte value 104.
'    The String value 103.0 is not in a recognizable format.
'    Converted the String value -1 to the SByte 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 SByte value 100.

另请参阅

适用于

ToSByte(Object, IFormatProvider)

重要

此 API 不符合 CLS。

使用指定的区域性特定格式信息,将指定对象的值转换为 8 位带符号整数。

public:
 static System::SByte ToSByte(System::Object ^ value, IFormatProvider ^ provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object value, IFormatProvider provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object? value, IFormatProvider? provider);
[<System.CLSCompliant(false)>]
static member ToSByte : obj * IFormatProvider -> sbyte
Public Shared Function ToSByte (value As Object, provider As IFormatProvider) As SByte

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

SByte

一个与 value 等效的 8 位带符号整数,如果 valuenull,则为零。

属性

例外

value 的格式不正确。

value 不实现 IConvertible 接口。

  • 或 -

不支持该转换。

value 表示一个小于 MinValue 或大于 MaxValue 的数字。

示例

以下示例定义一个 ByteString 类,该类将有符号字节和无符号字节存储为十六进制字符串,以及指示字节符号的字段。 ByteString 类实现 IConvertible 接口。 其 IConvertible.ToSByte 方法调用 Parse(String, IFormatProvider) 该方法来执行转换。 如果失败,则会引发一个 OverflowException

using System;
using System.Globalization;

public enum SignBit { Negative=-1, Zero=0, Positive=1 };

public struct ByteString : IConvertible
{
   private SignBit signBit;
   private string byteString;

   public SignBit Sign
   {
      set { signBit = value; }
      get { return signBit; }
   }

   public string Value
   {
      set {
         if (value.Trim().Length > 2)
            throw new ArgumentException("The string representation of a byte cannot have more than two characters.");
         else
            byteString = value;
      }
      get { return byteString; }
   }

   // IConvertible implementations.
   public TypeCode GetTypeCode() {
      return TypeCode.Object;
   }

   public bool ToBoolean(IFormatProvider provider)
   {
      if (signBit == SignBit.Zero)
         return false;
      else
         return true;
   }

   public byte ToByte(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is out of range of the Byte type.", Convert.ToSByte(byteString, 16)));
      else
         return Byte.Parse(byteString, NumberStyles.HexNumber);
   }

   public char ToChar(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative) {
         throw new OverflowException(String.Format("{0} is out of range of the Char type.", Convert.ToSByte(byteString, 16)));
      }
      else {
         byte byteValue = Byte.Parse(this.byteString, NumberStyles.HexNumber);
         return Convert.ToChar(byteValue);
      }
   }

   public DateTime ToDateTime(IFormatProvider provider)
   {
      throw new InvalidCastException("ByteString to DateTime conversion is not supported.");
   }

   public decimal ToDecimal(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
      {
         sbyte byteValue = SByte.Parse(byteString, NumberStyles.HexNumber);
         return Convert.ToDecimal(byteValue);
      }
      else
      {
         byte byteValue = Byte.Parse(byteString, NumberStyles.HexNumber);
         return Convert.ToDecimal(byteValue);
      }
   }

   public double ToDouble(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToDouble(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToDouble(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public short ToInt16(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt16(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToInt16(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public int ToInt32(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt32(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToInt32(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public long ToInt64(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt64(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToInt64(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public sbyte ToSByte(IFormatProvider provider)
   {
      try {
         return SByte.Parse(byteString, NumberStyles.HexNumber);
      }
      catch (OverflowException e) {
         throw new OverflowException(String.Format("{0} is outside the range of the SByte type.",
                                                   Byte.Parse(byteString, NumberStyles.HexNumber)), e);
      }
   }

   public float ToSingle(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToSingle(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToSingle(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public string ToString(IFormatProvider provider)
   {
      return "0x" + this.byteString;
   }

   public object ToType(Type conversionType, IFormatProvider provider)
   {
      switch (Type.GetTypeCode(conversionType))
      {
         case TypeCode.Boolean:
            return this.ToBoolean(null);
         case TypeCode.Byte:
            return this.ToByte(null);
         case TypeCode.Char:
            return this.ToChar(null);
         case TypeCode.DateTime:
            return this.ToDateTime(null);
         case TypeCode.Decimal:
            return this.ToDecimal(null);
         case TypeCode.Double:
            return this.ToDouble(null);
         case TypeCode.Int16:
            return this.ToInt16(null);
         case TypeCode.Int32:
            return this.ToInt32(null);
         case TypeCode.Int64:
            return this.ToInt64(null);
         case TypeCode.Object:
            if (typeof(ByteString).Equals(conversionType))
               return this;
            else
               throw new InvalidCastException(String.Format("Conversion to a {0} is not supported.", conversionType.Name));
         case TypeCode.SByte:
            return this.ToSByte(null);
         case TypeCode.Single:
            return this.ToSingle(null);
         case TypeCode.String:
            return this.ToString(null);
         case TypeCode.UInt16:
            return this.ToUInt16(null);
         case TypeCode.UInt32:
            return this.ToUInt32(null);
         case TypeCode.UInt64:
            return this.ToUInt64(null);
         default:
            throw new InvalidCastException(String.Format("Conversion to {0} is not supported.", conversionType.Name));
      }
   }

   public UInt16 ToUInt16(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt16 type.",
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)));
      else
         return Convert.ToUInt16(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public UInt32 ToUInt32(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt32 type.",
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)));
      else
         return Convert.ToUInt32(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public UInt64 ToUInt64(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt64 type.",
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)));
      else
         return Convert.ToUInt64(Byte.Parse(byteString, NumberStyles.HexNumber));
   }
}
open System
open System.Globalization

type SignBit =
   | Negative = -1
   | Zero = 0
   | Positive = 1

[<Struct>]
type ByteString =
    val mutable private byteString: string

    val mutable Sign : SignBit

    member this.Value
        with get () = this.byteString
        and set (value: string) =
            if value.Trim().Length > 2 then
                invalidArg "value" "The string representation of a byte cannot have more than two characters."
            this.byteString <- value

    // IConvertible implementations.
    interface IConvertible with
        member _.GetTypeCode() = 
            TypeCode.Object

        member this.ToBoolean(provider: IFormatProvider) =
            this.Sign <> SignBit.Zero

        member this.ToByte(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{Convert.ToSByte(this.byteString, 16)} is out of range of the Byte type.")
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)

        member this.ToChar(provider: IFormatProvider) =
        
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{Convert.ToSByte(this.byteString, 16)} is out of range of the Char type.")
            else
                let byteValue = Byte.Parse(this.byteString, NumberStyles.HexNumber)
                Convert.ToChar byteValue

        member _.ToDateTime(provider: IFormatProvider) =    
            raise (InvalidCastException "ByteString to DateTime conversion is not supported.")

        member this.ToDecimal(provider: IFormatProvider) =    
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDecimal
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDecimal

        member this.ToDouble(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDouble
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDouble

        member this.ToInt16(provider: IFormatProvider) =    
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt16
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt16

        member this.ToInt32(provider: IFormatProvider) =    
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt32
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt32

        member this.ToInt64(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt64
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt64

        member this.ToSByte(provider: IFormatProvider) =    
            try
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
            with :? OverflowException as e ->
                raise (OverflowException($"{Byte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the SByte type.", e) )

        member this.ToSingle(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToSingle
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToSingle

        member this.ToString(provider: IFormatProvider) =
            "0x" + this.byteString

        member this.ToType(conversionType: Type, provider: IFormatProvider) =
            let this = this :> IConvertible
            match Type.GetTypeCode conversionType with
            | TypeCode.Boolean ->
                this.ToBoolean null
            | TypeCode.Byte ->
                this.ToByte null
            | TypeCode.Char ->
                this.ToChar null
            | TypeCode.DateTime ->
                this.ToDateTime null
            | TypeCode.Decimal ->
                this.ToDecimal null
            | TypeCode.Double ->
                this.ToDouble null
            | TypeCode.Int16 ->
                this.ToInt16 null
            | TypeCode.Int32 ->
                this.ToInt32 null
            | TypeCode.Int64 ->
                this.ToInt64 null
            | TypeCode.Object ->
                if typeof<ByteString>.Equals conversionType then
                    this
                else
                    raise (InvalidCastException $"Conversion to a {conversionType.Name} is not supported.")
            | TypeCode.SByte ->
                this.ToSByte null
            | TypeCode.Single ->
                this.ToSingle null
            | TypeCode.String ->
                this.ToString null
            | TypeCode.UInt16 ->
                this.ToUInt16 null
            | TypeCode.UInt32 ->
                this.ToUInt32 null
            | TypeCode.UInt64 ->
                this.ToUInt64 null
            | _ ->
                raise (InvalidCastException $"Conversion to {conversionType.Name} is not supported.")

        member this.ToUInt16(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{SByte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the UInt16 type." )
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToUInt16

        member this.ToUInt32(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{SByte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the UInt32 type.")
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToUInt32
    
        member this.ToUInt64(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{SByte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the UInt32 type.")
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToUInt64
Imports System.Globalization

Public Enum SignBit As Integer
   Positive = 1
   Zero = 0
   Negative = -1
End Enum

Public Structure ByteString : Implements IConvertible
   Private signBit As SignBit
   Private byteString As String
   
   Public Property Sign As SignBit
      Set
         signBit = value
      End Set
      Get
         Return signBit
      End Get
   End Property
   
   Public Property Value As String
      Set
         If value.Trim().Length > 2 Then
            Throw New ArgumentException("The string representation of a byte cannot have more than two characters.")
         Else
            byteString = value
         End If   
      End Set
      Get
         Return byteString
      End Get
   End Property
   
   ' IConvertible implementations.
   Public Function GetTypeCode() As TypeCode _
                   Implements IConvertible.GetTypeCode
      Return TypeCode.Object
   End Function
   
   Public Function ToBoolean(provider As IFormatProvider) As Boolean _
                   Implements IConvertible.ToBoolean
      If signBit = SignBit.Zero Then
         Return False
      Else
         Return True
      End If
   End Function 
   
   Public Function ToByte(provider As IFormatProvider) As Byte _
                   Implements IConvertible.ToByte
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is out of range of the Byte type.", Convert.ToSByte(byteString, 16))) 
      Else
         Return Byte.Parse(byteString, NumberStyles.HexNumber)
      End If       
   End Function
   
   Public Function ToChar(provider As IFormatProvider) As Char _
                   Implements IConvertible.ToChar
      If signBit = signBit.Negative Then 
         Throw New OverflowException(String.Format("{0} is out of range of the Char type.", Convert.ToSByte(byteString, 16)))
      Else
         Dim byteValue As Byte = Byte.Parse(Me.byteString, NumberStyles.HexNumber)
         Return Convert.ToChar(byteValue)
      End If                
   End Function 
   
   Public Function ToDateTime(provider As IFormatProvider) As Date _
                   Implements IConvertible.ToDateTime
      Throw New InvalidCastException("ByteString to DateTime conversion is not supported.")
   End Function
   
   Public Function ToDecimal(provider As IFormatProvider) As Decimal _
                   Implements IConvertible.ToDecimal
      If signBit = signBit.Negative Then
         Dim byteValue As SByte = SByte.Parse(byteString, NumberStyles.HexNumber)
         Return Convert.ToDecimal(byteValue)
      Else
         Dim byteValue As Byte = Byte.Parse(byteString, NumberStyles.HexNumber)
         Return Convert.ToDecimal(byteValue)
      End If
   End Function
   
   Public Function ToDouble(provider As IFormatProvider) As Double _
                   Implements IConvertible.ToDouble
      If signBit = signBit.Negative Then
         Return Convert.ToDouble(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToDouble(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function   
   
   Public Function ToInt16(provider As IFormatProvider) As Int16 _
                   Implements IConvertible.ToInt16
      If signBit = signBit.Negative Then
         Return Convert.ToInt16(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToInt16(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToInt32(provider As IFormatProvider) As Int32 _
                   Implements IConvertible.ToInt32
      If signBit = signBit.Negative Then
         Return Convert.ToInt32(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToInt32(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToInt64(provider As IFormatProvider) As Int64 _
                   Implements IConvertible.ToInt64
      If signBit = signBit.Negative Then
         Return Convert.ToInt64(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToInt64(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToSByte(provider As IFormatProvider) As SByte _
                   Implements IConvertible.ToSByte
      Try
         Return SByte.Parse(byteString, NumberStyles.HexNumber)
      Catch e As OverflowException
         Throw New OverflowException(String.Format("{0} is outside the range of the SByte type.", _
                                                   Byte.Parse(byteString, NumberStyles.HexNumber)))
      End Try   
   End Function

   Public Function ToSingle(provider As IFormatProvider) As Single _
                   Implements IConvertible.ToSingle
      If signBit = signBit.Negative Then
         Return Convert.ToSingle(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToSingle(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function

   Public Overloads Function ToString(provider As IFormatProvider) As String _
                   Implements IConvertible.ToString
      Return Me.byteString
   End Function
   
   Public Function ToType(conversionType As Type, provider As IFormatProvider) As Object _
                   Implements IConvertible.ToType
      Select Case Type.GetTypeCode(conversionType)
         Case TypeCode.Boolean 
            Return Me.ToBoolean(Nothing)
         Case TypeCode.Byte
            Return Me.ToByte(Nothing)
         Case TypeCode.Char
            Return Me.ToChar(Nothing)
         Case TypeCode.DateTime
            Return Me.ToDateTime(Nothing)
         Case TypeCode.Decimal
            Return Me.ToDecimal(Nothing)
         Case TypeCode.Double
            Return Me.ToDouble(Nothing)
         Case TypeCode.Int16
            Return Me.ToInt16(Nothing)
         Case TypeCode.Int32
            Return Me.ToInt32(Nothing)
         Case TypeCode.Int64
            Return Me.ToInt64(Nothing)
         Case TypeCode.Object
            If GetType(ByteString).Equals(conversionType) Then
               Return Me
            Else
               Throw New InvalidCastException(String.Format("Conversion to a {0} is not supported.", conversionType.Name))
            End If 
         Case TypeCode.SByte
            Return Me.ToSByte(Nothing)
         Case TypeCode.Single
            Return Me.ToSingle(Nothing)
         Case TypeCode.String
            Return Me.ToString(Nothing)
         Case TypeCode.UInt16
            Return Me.ToUInt16(Nothing)
         Case TypeCode.UInt32
            Return Me.ToUInt32(Nothing)
         Case TypeCode.UInt64
            Return Me.ToUInt64(Nothing)   
         Case Else
            Throw New InvalidCastException(String.Format("Conversion to {0} is not supported.", conversionType.Name))   
            
      End Select
   End Function
   
   Public Function ToUInt16(provider As IFormatProvider) As UInt16 _
                   Implements IConvertible.ToUInt16
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is outside the range of the UInt16 type.", _
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)))
      Else
         Return Convert.ToUInt16(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function

   Public Function ToUInt32(provider As IFormatProvider) As UInt32 _
                   Implements IConvertible.ToUInt32
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is outside the range of the UInt32 type.", _
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)))
      Else
         Return Convert.ToUInt32(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToUInt64(provider As IFormatProvider) As UInt64 _
                   Implements IConvertible.ToUInt64
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is outside the range of the UInt64 type.", _
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)))
      Else
         Return Convert.ToUInt64(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
End Structure

下面的示例演示如何IConvertible.ToSByte通过Convert.ToSByte(Object, IFormatProvider)该方法调用类的实现ByteString

public class Class1
{
   public static void Main()
   {
      sbyte positiveByte = 120;
      sbyte negativeByte = -101;

      ByteString positiveString = new ByteString();
      positiveString.Sign = (SignBit) Math.Sign(positiveByte);
      positiveString.Value = positiveByte.ToString("X2");

      ByteString negativeString = new ByteString();
      negativeString.Sign = (SignBit) Math.Sign(negativeByte);
      negativeString.Value = negativeByte.ToString("X2");

      try {
         Console.WriteLine("'{0}' converts to {1}.", positiveString.Value, Convert.ToSByte(positiveString));
      }
      catch (OverflowException) {
         Console.WriteLine("0x{0} is outside the range of the Byte type.", positiveString.Value);
      }

      try {
         Console.WriteLine("'{0}' converts to {1}.", negativeString.Value, Convert.ToSByte(negativeString));
      }
      catch (OverflowException) {
         Console.WriteLine("0x{0} is outside the range of the Byte type.", negativeString.Value);
      }
   }
}
// The example displays the following output:
//       '78' converts to 120.
//       '9B' converts to -101.
let positiveByte = 120y
let negativeByte = -101y

let mutable positiveString = ByteString()
positiveString.Sign <- sign positiveByte |> enum
positiveString.Value <- positiveByte.ToString "X2"

let mutable negativeString = ByteString()
negativeString.Sign <- sign negativeByte |> enum
negativeString.Value <- negativeByte.ToString "X2"

try
    printfn $"'{positiveString.Value}' converts to {Convert.ToSByte positiveString}."
with :? OverflowException ->
    printfn $"0x{positiveString.Value} is outside the range of the Byte type."

try
    printfn $"'{negativeString.Value}' converts to {Convert.ToSByte negativeString}."
with :? OverflowException ->
    printfn $"0x{negativeString.Value} is outside the range of the Byte type."

// The example displays the following output:
//       '78' converts to 120.
//       '9B' converts to -101.
Module modMain
   Public Sub Main()
      Dim positiveByte As SByte = 120
      Dim negativeByte As SByte = -101
      
      
      Dim positiveString As New ByteString()
      positiveString.Sign = CType(Math.Sign(positiveByte), SignBit)
      positiveString.Value = positiveByte.ToString("X2")
      
      Dim negativeString As New ByteString()
      negativeString.Sign = CType(Math.Sign(negativeByte), SignBit)
      negativeString.Value = negativeByte.ToString("X2")
      
      Try
         Console.WriteLine("'{0}' converts to {1}.", positiveString.Value, Convert.ToSByte(positiveString))
      Catch e As OverflowException
         Console.WriteLine("0x{0} is outside the range of the Byte type.", positiveString.Value)
      End Try

      Try
         Console.WriteLine("'{0}' converts to {1}.", negativeString.Value, Convert.ToSByte(negativeString))
      Catch e As OverflowException
         Console.WriteLine("0x{0} is outside the range of the Byte type.", negativeString.Value)
      End Try   
   End Sub
End Module
' The example dosplays the following output:
'       '78' converts to 120.
'       '9B' converts to -101.

注解

provider 使用户能够指定有关内容 value区域性特定的转换信息。 例如,如果 value 表示 String 一个数字, provider 则可能会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 IConvertible 接口的用户定义类型,可以使用此参数。

适用于

ToSByte(SByte)

重要

此 API 不符合 CLS。

返回指定的 8 位有符号整数;不执行实际的转换。

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

参数

value
SByte

要转换的 8 位无符号整数。

返回

SByte

不经更改即返回 value

属性

适用于

ToSByte(Int32)

重要

此 API 不符合 CLS。

将指定的 32 位有符号整数的值转换为等效的 8 位有符号整数。

public:
 static System::SByte ToSByte(int value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (int value);
[<System.CLSCompliant(false)>]
static member ToSByte : int -> sbyte
Public Shared Function ToSByte (value As Integer) As SByte

参数

value
Int32

要转换的 32 位带符号整数。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将带符号整数数组中的每个元素转换为有符号字节。

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

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

for number in numbers do
    try
        let result = Convert.ToSByte 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 SByte type."
// The example displays the following output:
//    The Int32 value -2147483647 is outside the range of the SByte type.
//    Converted the Int32 value -1 to the SByte value -1.
//    Converted the Int32 value 0 to the SByte value 0.
//    Converted the Int32 value 121 to the SByte value 121.
//    Converted the Int32 value 340 to the SByte value 340.
//    The Int32 value 2147483647 is outside the range of the SByte type.
Dim numbers() As Integer = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue }
Dim result As SByte
For Each number As Integer In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int32 value -2147483648 is outside the range of the SByte type.
'    Converted the Int32 value -1 to the SByte value -1.
'    Converted the Int32 value 0 to the SByte value 0.
'    Converted the Int32 value 121 to the SByte value 121.
'    The Int32 value 340 is outside the range of the SByte type.
'    The Int32 value 2147483647 is outside the range of the SByte type.

适用于

ToSByte(Int64)

重要

此 API 不符合 CLS。

将指定的 64 位有符号整数的值转换为等效的 8 位有符号整数。

public:
 static System::SByte ToSByte(long value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (long value);
[<System.CLSCompliant(false)>]
static member ToSByte : int64 -> sbyte
Public Shared Function ToSByte (value As Long) As SByte

参数

value
Int64

要转换的 64 位带符号整数。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将长整数数组中的每个元素转换为带符号字节。

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

for number in numbers do
    try
        let result = Convert.ToSByte 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 SByte type."
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the SByte type.
//    Converted the Int64 value -1 to the SByte value -1.
//    Converted the Int64 value 0 to the SByte value 0.
//    Converted the Int64 value 121 to the SByte value 121.
//    Converted the Int64 value 340 to the SByte value 340.
//    The Int64 value 9223372036854775807 is outside the range of the SByte type.
Dim numbers() As Long = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue }
Dim result As SByte
For Each number As Long In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int64 value -9223372036854775808 is outside the range of the SByte type.
'    Converted the Int64 value -1 to the SByte value -1.
'    Converted the Int64 value 0 to the SByte value 0.
'    Converted the Int64 value 121 to the SByte value 121.
'    The Int64 value 340 is outside the range of the SByte type.
'    The Int64 value 9223372036854775807 is outside the range of the SByte type.

适用于

ToSByte(Object)

重要

此 API 不符合 CLS。

将指定对象的值转换为 8 位带符号整数。

public:
 static System::SByte ToSByte(System::Object ^ value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object? value);
[<System.CLSCompliant(false)>]
static member ToSByte : obj -> sbyte
Public Shared Function ToSByte (value As Object) As SByte

参数

value
Object

用于实现 IConvertible 接口的对象,或为 null

返回

SByte

一个与 value 等效的 8 位带符号整数,如果 valuenull,则为零。

属性

例外

value 的格式不正确。

value 不实现 IConvertible 接口。

  • 或 -

不支持该转换。

value 表示一个小于 MinValue 或大于 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有符号字节。

object[] values = { true, -12, 163, 935, 'x', "104", "103.0", "-1",
                    "1.00e2", "One", 1.00e2};
sbyte result;

foreach (object value in values)
{
   try {
      result = Convert.ToSByte(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 SByte 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 a Byte exists for the {0} value {1}.",
                        value.GetType().Name, value);
   }
}
// The example displays the following output:
//    Converted the Boolean value true to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    The Int32 value 163 is outside the range of the SByte type.
//    The Int32 value 935 is outside the range of the SByte type.
//    Converted the Char value x to the SByte value 120.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte 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 SByte value 100.
let values: obj[] = 
    [| true; -12; 163; 935; 'x'; DateTime(2009, 5, 12)
       "104"; "103.0"; "-1"
       "1.00e2"; "One"; 1.00e2; 16.3e42 |]

for value in values do
    try
        let result = Convert.ToSByte 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 SByte type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value {value} is not in a recognizable format."
    | :? InvalidCastException ->
        printfn $"No conversion to an SByte exists for the {value.GetType().Name} value {value}."
// The example displays the following output:
//    Converted the Boolean value True to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    Converted the Int32 value 163 to the SByte value 163.
//    Converted the Int32 value 935 to the SByte value 935.
//    Converted the Char value x to the SByte value 120.
//    No conversion to an SByte exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte 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 SByte value 100.
//    The Double value 1.63E+43 is outside the range of the SByte type.
Dim values() As Object = { True, -12, 163, 935, "x"c, "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2}
Dim result As SByte
For Each value As Object In values
   Try
      result = Convert.ToSByte(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 SByte 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 a Byte 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 SByte value 1.
'    Converted the Int32 value -12 to the SByte value -12.
'    The Int32 value 163 is outside the range of the SByte type.
'    The Int32 value 935 is outside the range of the SByte type.
'    Converted the Char value x to the SByte value 120.
'    Converted the String value 104 to the SByte value 104.
'    The String value 103.0 is not in a recognizable format.
'    Converted the String value -1 to the SByte 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 SByte value 100.

注解

返回值是调用 IConvertible.ToSByte 基础类型的 value方法的结果。

适用于

ToSByte(Byte)

重要

此 API 不符合 CLS。

将指定的 8 位无符号整数的值转换为等效的 8 位有符号整数。

public:
 static System::SByte ToSByte(System::Byte value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (byte value);
[<System.CLSCompliant(false)>]
static member ToSByte : byte -> sbyte
Public Shared Function ToSByte (value As Byte) As SByte

参数

value
Byte

要转换的 8 位无符号整数。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue

示例

以下示例尝试将字节数组中的每个元素转换为有符号字节。

byte[] numbers = { Byte.MinValue, 10, 100, Byte.MaxValue };
sbyte result;

foreach (byte number in numbers)
{
   try {
      result = Convert.ToSByte(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 SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the Byte value 0 to the SByte value 0.
//    Converted the Byte value 10 to the SByte value 10.
//    Converted the Byte value 100 to the SByte value 100.
//    The Byte value 255 is outside the range of the SByte type.
let bytes = 
    [| Byte.MinValue; 14uy; 122uy; Byte.MaxValue |]

for byteValue in bytes do
    let result = Convert.ToSByte byteValue
    printfn $"Converted the {byteValue.GetType().Name} value {byteValue} to the {result.GetType().Name} value {result}."
// The example displays the following output:
//       Converted the Byte value 0 to the SByte value 0.
//       Converted the Byte value 14 to the SByte value 14.
//       Converted the Byte value 122 to the SByte value 122.
//       Converted the Byte value 255 to the SByte value 255.
Dim numbers() As Byte = { Byte.MinValue, 10, 100, Byte.MaxValue }
Dim result As SByte
For Each number As Byte In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the Byte value 0 to the SByte value 0.
'    Converted the Byte value 10 to the SByte value 10.
'    Converted the Byte value 100 to the SByte value 100.
'    The Byte value 255 is outside the range of the SByte type.

适用于

ToSByte(Char)

重要

此 API 不符合 CLS。

将指定的 Unicode 字符的值转换为等效的 8 位有符号整数。

public:
 static System::SByte ToSByte(char value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (char value);
[<System.CLSCompliant(false)>]
static member ToSByte : char -> sbyte
Public Shared Function ToSByte (value As Char) As SByte

参数

value
Char

要转换的 Unicode 字符。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue

示例

以下示例尝试将值数组 Char 中的每个元素转换为带符号字节。

char[] chars = { 'a', 'z', '\u0007', '\u0200', '\u1023' };
foreach (char ch in chars)
{
   try {
      sbyte result = Convert.ToSByte(ch);
      Console.WriteLine("{0} is converted to {1}.", ch, result);
   }
   catch (OverflowException) {
      Console.WriteLine("Unable to convert u+{0} to a byte.",
                        Convert.ToInt16(ch).ToString("X4"));
   }
}
// The example displays the following output:
//    a is converted to 97.
//    z is converted to 122.
//     is converted to 7.
//    Unable to convert u+00C8 to a byte.
//    Unable to convert u+03FF to a byte.
let chars = 
    [| 'a'; 'z'; '\u0007'; '\u03FF'; '\u7FFF'; '\uFFFE' |]

for ch in chars do
    try
        let result = Convert.ToSByte ch
        printfn $"Converted the {ch.GetType().Name} value '{ch}' to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"Unable to convert u+{int ch:X4} to an Int32."
// The example displays the following output:
//       Converted the Char value 'a' to the SByte value 97.
//       Converted the Char value 'z' to the SByte value 122.
//       Converted the Char value '' to the SByte value 7.
//       Converted the Char value 'Ͽ' to the SByte value 1023.
//       Converted the Char value '翿' to the SByte value 32767.
//       Converted the Char value '￾' to the SByte value 65534.
Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(200), ChrW(1023) }
For Each ch As Char in chars
   Try
      Dim result As SByte = Convert.ToSByte(ch)
      Console.WriteLine("{0} is converted to {1}.", ch, result)
   Catch e As OverflowException
      Console.WriteLine("Unable to convert u+{0} to a byte.", _
                        AscW(ch).ToString("X4"))
   End Try
Next   
' The example displays the following output:
'    a is converted to 97.
'    z is converted to 122.
'     is converted to 7.
'    Unable to convert u+00C8 to a byte.
'    Unable to convert u+03FF to a byte.

适用于

ToSByte(DateTime)

重要

此 API 不符合 CLS。

调用此方法始终引发 InvalidCastException

public:
 static System::SByte ToSByte(DateTime value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (DateTime value);
[<System.CLSCompliant(false)>]
static member ToSByte : DateTime -> sbyte
Public Shared Function ToSByte (value As DateTime) As SByte

参数

value
DateTime

要转换的日期和时间值。

返回

SByte

不支持此转换。 不返回任何值。

属性

例外

不支持此转换。

适用于

ToSByte(Boolean)

重要

此 API 不符合 CLS。

将指定的布尔值转换为等效的 8 位带符号整数。

public:
 static System::SByte ToSByte(bool value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (bool value);
[<System.CLSCompliant(false)>]
static member ToSByte : bool -> sbyte
Public Shared Function ToSByte (value As Boolean) As SByte

参数

value
Boolean

要转换的布尔值。

返回

SByte

如果 valuetrue,则为数字 1;否则,为 0。

属性

示例

以下示例将布尔值 truefalse 带符号字节值转换为符号字节值。

bool falseFlag = false;
bool trueFlag = true;

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

适用于

ToSByte(Double)

重要

此 API 不符合 CLS。

将指定的双精度浮点数的值转换为等效的 8 位带符号整数。

public:
 static System::SByte ToSByte(double value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (double value);
[<System.CLSCompliant(false)>]
static member ToSByte : double -> sbyte
Public Shared Function ToSByte (value As Double) As SByte

参数

value
Double

要转换的双精度浮点数。

返回

SByte

value,舍入为最接近的 8 位有符号整数。 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。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将值数组 Double 中的每个元素转换为带符号字节。

double[] numbers = { Double.MinValue, -129.5, -12.7, 0, 16,
                     103.6, 255.0, 1.63509e17, Double.MaxValue};
sbyte result;

foreach (double number in numbers)
{
   try {
      result = Convert.ToSByte(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 SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Double value -1.79769313486232E+308 is outside the range of the SByte type.
//    The Double value -129.5 is outside the range of the SByte type.
//    Converted the Double value -12.7 to the SByte value -13.
//    Converted the Double value 0 to the SByte value 0.
//    Converted the Double value 16 to the SByte value 16.
//    Converted the Double value 103.6 to the SByte value 104.
//    The Double value 255 is outside the range of the SByte type.
//    The Double value 1.63509E+17 is outside the range of the SByte type.
//    The Double value 1.79769313486232E+308 is outside the range of the SByte 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.ToSByte 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 SByte type."
//    -1.79769313486232E+308 is outside the range of the SByte type.
//    -13800000000 is outside the range of the SByte type.
//    Converted the Double value '-1023.299' to the SByte value -1023.
//    Converted the Double value '-12.98' to the SByte value -13.
//    Converted the Double value '0' to the SByte value 0.
//    Converted the Double value '9.113E-16' to the SByte value 0.
//    Converted the Double value '103.919' to the SByte value 104.
//    Converted the Double value '17834.191' to the SByte value 17834.
//    1.79769313486232E+308 is outside the range of the SByte type.
Dim numbers() As Double = { Double.MinValue, -129.5, -12.7, 0, 16, _
                            103.6, 255.0, 1.63509e17, Double.MaxValue}
Dim result As SByte

For Each number As Double In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next                                  
' The example displays the following output:
'    The Double value -1.79769313486232E+308 is outside the range of the SByte type.
'    The Double value -129.5 is outside the range of the SByte type.
'    Converted the Double value -12.7 to the SByte value -13.
'    Converted the Double value 0 to the SByte value 0.
'    Converted the Double value 16 to the SByte value 16.
'    Converted the Double value 103.6 to the SByte value 104.
'    The Double value 255 is outside the range of the SByte type.
'    The Double value 1.63509E+17 is outside the range of the SByte type.
'    The Double value 1.79769313486232E+308 is outside the range of the SByte type.

另请参阅

适用于

ToSByte(Int16)

重要

此 API 不符合 CLS。

将指定的 16 位带符号整数的值转换为等效的 8 位带符号整数。

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

参数

value
Int16

要转换的 16 位带符号整数。

返回

SByte

一个与 value 等效的 8 位带符号整数。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将有符号 16 位整数数组中的每个元素转换为有符号字节。

short[] numbers = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue };
sbyte result;
foreach (short number in numbers)
{
   try {
      result = Convert.ToSByte(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 SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Int16 value -32768 is outside the range of the SByte type.
//    Converted the Int16 value -1 to the SByte value -1.
//    Converted the Int16 value 0 to the SByte value 0.
//    Converted the Int16 value 121 to the SByte value 121.
//    The Int16 value 340 is outside the range of the SByte type.
//    The Int16 value 32767 is outside the range of the SByte type.
let numbers = 
    [| Int16.MinValue; -1s; 0s; 121s; 340s; Int16.MaxValue |]

for number in numbers do
    let result = Convert.ToSByte number
    printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
// The example displays the following output:
//    Converted the Int16 value -32768 to a Int64 value -32768.
//    Converted the Int16 value -1 to a Int64 value -1.
//    Converted the Int16 value 0 to a Int64 value 0.
//    Converted the Int16 value 121 to a Int64 value 121.
//    Converted the Int16 value 340 to a Int64 value 340.
//    Converted the Int16 value 32767 to a Int64 value 32767.
Dim numbers() As Short = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue }
Dim result As SByte
For Each number As Short In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int16 value -32768 is outside the range of the SByte type.
'    Converted the Int16 value -1 to the SByte value -1.
'    Converted the Int16 value 0 to the SByte value 0.
'    Converted the Int16 value 121 to the SByte value 121.
'    The Int16 value 340 is outside the range of the SByte type.
'    The Int16 value 32767 is outside the range of the SByte type.

适用于

ToSByte(Decimal)

重要

此 API 不符合 CLS。

将指定的十进制数的值转换为等效的 8 位带符号整数。

public:
 static System::SByte ToSByte(System::Decimal value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (decimal value);
[<System.CLSCompliant(false)>]
static member ToSByte : decimal -> sbyte
Public Shared Function ToSByte (value As Decimal) As SByte

参数

value
Decimal

要转换的十进制数。

返回

SByte

value,舍入为最接近的 8 位有符号整数。 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。

属性

例外

value 大于 MaxValue 或小于 MinValue

示例

以下示例尝试将值数组 Decimal 中的每个元素转换为带符号字节。

decimal[] numbers = { Decimal.MinValue, -129.5m, -12.7m, 0m, 16m,
                      103.6m, 255.0m, Decimal.MaxValue };
sbyte result;

foreach (decimal number in numbers)
{
   try {
      result = Convert.ToSByte(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 SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Decimal value -79228162514264337593543950335 is outside the range of the SByte type.
//    The Decimal value -129.5 is outside the range of the SByte type.
//    Converted the Decimal value -12.7 to the SByte value -13.
//    Converted the Decimal value 0 to the SByte value 0.
//    Converted the Decimal value 16 to the SByte value 16.
//    Converted the Decimal value 103.6 to the SByte value 104.
//    The Decimal value 255 is outside the range of the SByte type.
//    The Decimal value 79228162514264337593543950335 is outside the range of the SByte type.
let values = 
    [| Decimal.MinValue; -1034.23m; -12m; 0m; 147m
       199.55m; 9214.16m; Decimal.MaxValue |]

for value in values do
    try
        let result = Convert.ToSByte 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 SByte type."
// The example displays the following output:
//    -79228162514264337593543950335 is outside the range of the SByte type.
//    Converted the Decimal value '-1034.23' to the SByte value -1034.
//    Converted the Decimal value '-12' to the SByte value -12.
//    Converted the Decimal value '0' to the SByte value 0.
//    Converted the Decimal value '147' to the SByte value 147.
//    Converted the Decimal value '199.55' to the SByte value 200.
//    Converted the Decimal value '9214.16' to the SByte value 9214.
//    79228162514264337593543950335 is outside the range of the SByte type.
Dim numbers() As Decimal = { Decimal.MinValue, -129.5d, -12.7d, 0d, 16d, _
                             103.6d, 255.0d, Decimal.MaxValue }
Dim result As SByte

For Each number As Decimal In numbers
   Try
      result = Convert.ToSByte(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 SByte type.", _
                        number.GetType().Name, number)
   End Try
Next                         
' The example displays the following output:
'    The Decimal value -79228162514264337593543950335 is outside the range of the SByte type.
'    The Decimal value -129.5 is outside the range of the SByte type.
'    Converted the Decimal value -12.7 to the SByte value -13.
'    Converted the Decimal value 0 to the SByte value 0.
'    Converted the Decimal value 16 to the SByte value 16.
'    Converted the Decimal value 103.6 to the SByte value 104.
'    The Decimal value 255 is outside the range of the SByte type.
'    The Decimal value 79228162514264337593543950335 is outside the range of the SByte type.

另请参阅

适用于