Convert.ToByte Convert.ToByte Convert.ToByte Convert.ToByte Method

Definizione

Converte un valore specificato in un intero senza segno a 8 bit.Converts a specified value to an 8-bit unsigned integer.

Overload

ToByte(String) ToByte(String) ToByte(String) ToByte(String)

Converte la rappresentazione di stringa specificata di un numero in un intero senza segno a 8 bit equivalente.Converts the specified string representation of a number to an equivalent 8-bit unsigned integer.

ToByte(UInt16) ToByte(UInt16) ToByte(UInt16) ToByte(UInt16)

Converte il valore dell'intero senza segno a 16 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 16-bit unsigned integer to an equivalent 8-bit unsigned integer.

ToByte(UInt32) ToByte(UInt32) ToByte(UInt32) ToByte(UInt32)

Converte il valore dell'intero senza segno a 32 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 32-bit unsigned integer to an equivalent 8-bit unsigned integer.

ToByte(String, Int32) ToByte(String, Int32) ToByte(String, Int32) ToByte(String, Int32)

Converte la rappresentazione di stringa di un numero in una base specificata nell'intero senza segno a 8 bit equivalente.Converts the string representation of a number in a specified base to an equivalent 8-bit unsigned integer.

ToByte(Object, IFormatProvider) ToByte(Object, IFormatProvider) ToByte(Object, IFormatProvider) ToByte(Object, IFormatProvider)

Converte il valore dell'oggetto specificato in un intero senza segno a 8 bit mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.Converts the value of the specified object to an 8-bit unsigned integer, using the specified culture-specific formatting information.

ToByte(String, IFormatProvider) ToByte(String, IFormatProvider) ToByte(String, IFormatProvider) ToByte(String, IFormatProvider)

Converte la rappresentazione di stringa specificata di un numero in un intero senza segno a 8 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.Converts the specified string representation of a number to an equivalent 8-bit unsigned integer, using specified culture-specific formatting information.

ToByte(Single) ToByte(Single) ToByte(Single) ToByte(Single)

Converte il valore del numero a virgola mobile a precisione singola specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified single-precision floating-point number to an equivalent 8-bit unsigned integer.

ToByte(UInt64) ToByte(UInt64) ToByte(UInt64) ToByte(UInt64)

Converte il valore dell'intero senza segno a 64 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 64-bit unsigned integer to an equivalent 8-bit unsigned integer.

ToByte(SByte) ToByte(SByte) ToByte(SByte) ToByte(SByte)

Converte il valore dell'intero con segno a 8 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 8-bit signed integer to an equivalent 8-bit unsigned integer.

ToByte(Double) ToByte(Double) ToByte(Double) ToByte(Double)

Converte il valore del numero a virgola mobile e con precisione doppia specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified double-precision floating-point number to an equivalent 8-bit unsigned integer.

ToByte(Int64) ToByte(Int64) ToByte(Int64) ToByte(Int64)

Converte il valore dell'intero con segno a 64 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 64-bit signed integer to an equivalent 8-bit unsigned integer.

ToByte(Byte) ToByte(Byte) ToByte(Byte) ToByte(Byte)

Restituisce l'intero senza segno a 8 bit specificato; non viene eseguita alcuna conversione effettiva.Returns the specified 8-bit unsigned integer; no actual conversion is performed.

ToByte(Char) ToByte(Char) ToByte(Char) ToByte(Char)

Converte il valore del carattere Unicode specificato nell'intero senza segno a 8 bit equivalente.Converts the value of the specified Unicode character to the equivalent 8-bit unsigned integer.

ToByte(DateTime) ToByte(DateTime) ToByte(DateTime) ToByte(DateTime)

La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.Calling this method always throws InvalidCastException.

ToByte(Boolean) ToByte(Boolean) ToByte(Boolean) ToByte(Boolean)

Converte il valore booleano specificato nell'intero senza segno a 8 bit equivalente.Converts the specified Boolean value to the equivalent 8-bit unsigned integer.

ToByte(Int16) ToByte(Int16) ToByte(Int16) ToByte(Int16)

Converte il valore dell'intero con segno a 16 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 16-bit signed integer to an equivalent 8-bit unsigned integer.

ToByte(Int32) ToByte(Int32) ToByte(Int32) ToByte(Int32)

Converte il valore dell'intero con segno a 32 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 32-bit signed integer to an equivalent 8-bit unsigned integer.

ToByte(Decimal) ToByte(Decimal) ToByte(Decimal) ToByte(Decimal)

Converte il valore del numero decimale specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified decimal number to an equivalent 8-bit unsigned integer.

ToByte(Object) ToByte(Object) ToByte(Object) ToByte(Object)

Converte il valore dell'oggetto specificato in un intero senza segno a 8 bit.Converts the value of the specified object to an 8-bit unsigned integer.

ToByte(String) ToByte(String) ToByte(String) ToByte(String)

Converte la rappresentazione di stringa specificata di un numero in un intero senza segno a 8 bit equivalente.Converts the specified string representation of a number to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(System::String ^ value);
public static byte ToByte (string value);
static member ToByte : string -> byte
Public Shared Function ToByte (value As String) As Byte

Parametri

value
String String String String

Stringa che contiene il numero da convertire.A string that contains the number to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value oppure zero se value è null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Eccezioni

value non è costituito da un segno facoltativo seguito da una sequenza di cifre (da 0 a 9).value does not consist of an optional sign followed by a sequence of digits (0 through 9).

L'oggetto value rappresenta un numero minore di MinValue o maggiore di MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene definita una matrice di stringhe e viene effettuato un tentativo di Byteconvertire ogni stringa in un oggetto.The following example defines a string array and attempts to convert each string to a Byte. Si noti che, null mentre una stringa viene analizzata String.Empty su zero FormatException, genera un'eccezione.Note that while a null string parses to zero, String.Empty throws a FormatException. Si noti inoltre che, mentre gli spazi iniziali e finali vengono analizzati correttamente, la formattazione dei simboli, ad esempio simboli di valuta, separatori di gruppi o separatori decimali, non.Also note that while leading and trailing spaces parse successfully, formatting symbols, such as currency symbols, group separators, or decimal separators, do not.

using System;

public class Example
{
   public static void Main()
   {
      String[] values = { null, "", "0xC9", "C9", "101", "16.3", 
                          "$12", "$12.01", "-4", "1,032", "255",
                          "   16  " };
      foreach (var value in values) {
         try {
            byte number = Convert.ToByte(value);
            Console.WriteLine("'{0}' --> {1}", 
                              value == null ? "<null>" : value, number);
         }
         catch (FormatException) {
            Console.WriteLine("Bad Format: '{0}'", 
                              value == null ? "<null>" : value);
         }
         catch (OverflowException) {
            Console.WriteLine("OverflowException: '{0}'", value);
         }
      }
   }
}
// The example displays the following output:
//     '<null>' --> 0
//     Bad Format: ''
//     Bad Format: '0xC9'
//     Bad Format: 'C9'
//     '101' --> 101
//     Bad Format: '16.3'
//     Bad Format: '$12'
//     Bad Format: '$12.01'
//     OverflowException: '-4'
//     Bad Format: '1,032'
//     '255' --> 255
//     '   16  ' --> 16
Module Example
   Public Sub Main()
      Dim values() As String = { Nothing, "", "0xC9", "C9", "101", 
                                 "16.3", "$12", "$12.01", "-4", 
                                 "1,032", "255", "   16  " }
      For Each value In values
         Try 
            Dim number As Byte = Convert.ToByte(value)
            Console.WriteLine("'{0}' --> {1}", 
                              If(value Is Nothing, "<null>", value), number)
         Catch e As FormatException
            Console.WriteLine("Bad Format: '{0}'", 
                              If(value Is Nothing, "<null>", value))
         Catch e As OverflowException
            Console.WriteLine("OverflowException: '{0}'", value)
         End Try
      Next
   End Sub
End Module
' The example displays the following output:
'     '<null>' --> 0
'     Bad Format: ''
'     Bad Format: '0xC9'
'     Bad Format: 'C9'
'     '101' --> 101
'     Bad Format: '16.3'
'     Bad Format: '$12'
'     Bad Format: '$12.01'
'     OverflowException: '-4'
'     Bad Format: '1,032'
'     '255' --> 255
'     '   16  ' --> 16

Commenti

L'utilizzo ToByte(String) del metodo equivale al passaggio value al Byte.Parse(String) metodo.Using the ToByte(String) method is equivalent to passing value to the Byte.Parse(String) method. value viene interpretato utilizzando le convenzioni di formattazione delle impostazioni cultura del thread corrente.value is interpreted by using the formatting conventions of the current thread culture.

Se si preferisce non gestire un'eccezione se la conversione non riesce, è invece possibile chiamare Byte.TryParse il metodo.If you prefer not to handle an exception if the conversion fails, you can call the Byte.TryParse method instead. Restituisce un Boolean valore che indica se la conversione ha avuto esito positivo o negativo.It returns a Boolean value that indicates whether the conversion succeeded or failed.

Vedi anche

ToByte(UInt16) ToByte(UInt16) ToByte(UInt16) ToByte(UInt16)

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero senza segno a 16 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 16-bit unsigned integer to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(System::UInt16 value);
[System.CLSCompliant(false)]
public static byte ToByte (ushort value);
static member ToByte : uint16 -> byte
Public Shared Function ToByte (value As UShort) As Byte

Parametri

value
UInt16 UInt16 UInt16 UInt16

Intero senza segno a 16 bit da convertire.The 16-bit unsigned integer to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

Esempi

Nell'esempio seguente viene convertita in valori una matrice di interi senza segno a Byte 16 bit.The following example converts an array of unsigned 16-bit integers to Byte values.

ushort[] numbers = { UInt16.MinValue, 121, 340, UInt16.MaxValue };
byte result;
foreach (ushort number in numbers)
{
   try {
      result = Convert.ToByte(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 Byte type.", 
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//       Converted the UInt16 value 0 to the Byte value 0.
//       Converted the UInt16 value 121 to the Byte value 121.
//       The UInt16 value 340 is outside the range of the Byte type.
//       The UInt16 value 65535 is outside the range of the Byte type.
Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As Byte
For Each number As UShort In numbers
   Try
      result = Convert.ToByte(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 Byte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'       Converted the UInt16 value 0 to the Byte value 0.
'       Converted the UInt16 value 121 to the Byte value 121.
'       The UInt16 value 340 is outside the range of the Byte type.
'       The UInt16 value 65535 is outside the range of the Byte type.

ToByte(UInt32) ToByte(UInt32) ToByte(UInt32) ToByte(UInt32)

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero senza segno a 32 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 32-bit unsigned integer to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(System::UInt32 value);
[System.CLSCompliant(false)]
public static byte ToByte (uint value);
static member ToByte : uint32 -> byte
Public Shared Function ToByte (value As UInteger) As Byte

Parametri

value
UInt32 UInt32 UInt32 UInt32

Intero senza segno a 32 bit da convertire.The 32-bit unsigned integer to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

Esempi

Nell'esempio seguente viene convertita una matrice di interi senza segno Byte in valori.The following example converts an array of unsigned integers to Byte values.

uint[] numbers = { UInt32.MinValue, 121, 340, UInt32.MaxValue };
byte result;
foreach (uint number in numbers)
{
   try {
      result = Convert.ToByte(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 Byte type.", 
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//       Converted the UInt32 value 0 to the Byte value 0.
//       Converted the UInt32 value 121 to the Byte value 121.
//       The UInt32 value 340 is outside the range of the Byte type.
//       The UInt32 value 4294967295 is outside the range of the Byte type.
Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As Byte
For Each number As UInteger In numbers
   Try
      result = Convert.ToByte(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 Byte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'       Converted the UInt32 value 0 to the Byte value 0.
'       Converted the UInt32 value 121 to the Byte value 121.
'       The UInt32 value 340 is outside the range of the Byte type.
'       The UInt32 value 4294967295 is outside the range of the Byte type.

ToByte(String, Int32) ToByte(String, Int32) ToByte(String, Int32) ToByte(String, Int32)

Converte la rappresentazione di stringa di un numero in una base specificata nell'intero senza segno a 8 bit equivalente.Converts the string representation of a number in a specified base to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(System::String ^ value, int fromBase);
public static byte ToByte (string value, int fromBase);
static member ToByte : string * int -> byte
Public Shared Function ToByte (value As String, fromBase As Integer) As Byte

Parametri

value
String String String String

Stringa che contiene il numero da convertire.A string that contains the number to convert.

fromBase
Int32 Int32 Int32 Int32

Base del numero in value, che deve essere 2, 8, 10 o 16.The base of the number in value, which must be 2, 8, 10, or 16.

Restituisce

Intero senza segno a 8 bit equivalente al numero in value oppure 0 (zero) se value è null.An 8-bit unsigned integer that is equivalent to the number in value, or 0 (zero) if value is null.

Eccezioni

Il valore di fromBase non è 2, 8, 10 o 16.fromBase is not 2, 8, 10, or 16.

In alternativa-or- value, che rappresenta un numero senza segno non in base 10, è preceduto da un segno negativo.value, which represents a non-base 10 unsigned number, is prefixed with a negative sign.

value contiene un carattere che corrisponde a una cifra non valida nella base specificata da fromBase.value contains a character that is not a valid digit in the base specified by fromBase. Il messaggio di eccezione indica che non ci sono cifre da convertire se il primo carattere in value non è valido; in caso contrario, il messaggio indica che value contiene caratteri finali non validi.The exception message indicates that there are no digits to convert if the first character in value is invalid; otherwise, the message indicates that value contains invalid trailing characters.

value, che rappresenta un numero senza segno in base 10, è preceduto da un segno negativo.value, which represents a base 10 unsigned number, is prefixed with a negative sign.

-oppure--or- L'oggetto value rappresenta un numero minore di MinValue o maggiore di MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene eseguito un tentativo alternativo di interpretare una matrice di stringhe come rappresentazione di valori binari, ottali, decimali ed esadecimali.The following example alternately attempts to interpret an array of strings as the representation of binary, octal, decimal, and hexadecimal values.

using System;

public class Example
{
   public static void Main()
   {
      int[] bases = { 2, 8, 10, 16 };
      string[] values = { "-1", "1", "08", "0F", "11" , "12", "30",                
                          "101", "255", "FF", "10000000", "80" };
      byte number;
      foreach (int numBase in bases)
      {
         Console.WriteLine("Base {0}:", numBase);
         foreach (string value in values)
         {
            try {
               number = Convert.ToByte(value, numBase);
               Console.WriteLine("   Converted '{0}' to {1}.", value, number);
            }   
            catch (FormatException) {
               Console.WriteLine("   '{0}' is not in the correct format for a base {1} byte value.", 
                                 value, numBase);
            }                     
            catch (OverflowException) {
               Console.WriteLine("   '{0}' is outside the range of the Byte type.", value);
            }   
            catch (ArgumentException) {
               Console.WriteLine("   '{0}' is invalid in base {1}.", value, numBase);
            }
         }                                 
      } 
   }
}
// The example displays the following output:
//    Base 2:
//       '-1' is invalid in base 2.
//       Converted '1' to 1.
//       '08' is not in the correct format for a base 2 conversion.
//       '0F' is not in the correct format for a base 2 conversion.
//       Converted '11' to 3.
//       '12' is not in the correct format for a base 2 conversion.
//       '30' is not in the correct format for a base 2 conversion.
//       Converted '101' to 5.
//       '255' is not in the correct format for a base 2 conversion.
//       'FF' is not in the correct format for a base 2 conversion.
//       Converted '10000000' to 128.
//       '80' is not in the correct format for a base 2 conversion.
//    Base 8:
//       '-1' is invalid in base 8.
//       Converted '1' to 1.
//       '08' is not in the correct format for a base 8 conversion.
//       '0F' is not in the correct format for a base 8 conversion.
//       Converted '11' to 9.
//       Converted '12' to 10.
//       Converted '30' to 24.
//       Converted '101' to 65.
//       Converted '255' to 173.
//       'FF' is not in the correct format for a base 8 conversion.
//       '10000000' is outside the range of the Byte type.
//       '80' is not in the correct format for a base 8 conversion.
//    Base 10:
//       '-1' is outside the range of the Byte type.
//       Converted '1' to 1.
//       Converted '08' to 8.
//       '0F' is not in the correct format for a base 10 conversion.
//       Converted '11' to 11.
//       Converted '12' to 12.
//       Converted '30' to 30.
//       Converted '101' to 101.
//       Converted '255' to 255.
//       'FF' is not in the correct format for a base 10 conversion.
//       '10000000' is outside the range of the Byte type.
//       Converted '80' to 80.
//    Base 16:
//       '-1' is invalid in base 16.
//       Converted '1' to 1.
//       Converted '08' to 8.
//       Converted '0F' to 15.
//       Converted '11' to 17.
//       Converted '12' to 18.
//       Converted '30' to 48.
//       '101' is outside the range of the Byte type.
//       '255' is outside the range of the Byte type.
//       Converted 'FF' to 255.
//       '10000000' is outside the range of the Byte type.
//       Converted '80' to 128.
Module Example
   Public Sub Main()
      Dim bases() As Integer = { 2, 8, 10, 16 }
      Dim values() As String = { "-1", "1", "08", "0F", "11" , "12", "30", _                
                                  "101", "255", "FF", "10000000", "80" }
      Dim number As Byte
      For Each base As Integer In bases
         Console.WriteLine("Base {0}:", base)
         For Each value As String In values
            Try
               number = Convert.ToByte(value, base)
               Console.WriteLine("   Converted '{0}' to {1}.", value, number)
            Catch e As FormatException
               Console.WriteLine("   '{0}' is not in the correct format for a base {1} conversion.", _
                                 value, base)
            Catch e As OverflowException
               Console.WriteLine("   '{0}' is outside the range of the Byte type.", value)
            Catch e As ArgumentException
               Console.WriteLine("   '{0}' is invalid in base {1}.", value, base)
            End Try   
         Next                                 
      Next 
   End Sub
End Module
' The example displays the following output:
'    Base 2:
'       '-1' is invalid in base 2.
'       Converted '1' to 1.
'       '08' is not in the correct format for a base 2 conversion.
'       '0F' is not in the correct format for a base 2 conversion.
'       Converted '11' to 3.
'       '12' is not in the correct format for a base 2 conversion.
'       '30' is not in the correct format for a base 2 conversion.
'       Converted '101' to 5.
'       '255' is not in the correct format for a base 2 conversion.
'       'FF' is not in the correct format for a base 2 conversion.
'       Converted '10000000' to 128.
'       '80' is not in the correct format for a base 2 conversion.
'    Base 8:
'       '-1' is invalid in base 8.
'       Converted '1' to 1.
'       '08' is not in the correct format for a base 8 conversion.
'       '0F' is not in the correct format for a base 8 conversion.
'       Converted '11' to 9.
'       Converted '12' to 10.
'       Converted '30' to 24.
'       Converted '101' to 65.
'       Converted '255' to 173.
'       'FF' is not in the correct format for a base 8 conversion.
'       '10000000' is outside the range of the Byte type.
'       '80' is not in the correct format for a base 8 conversion.
'    Base 10:
'       '-1' is outside the range of the Byte type.
'       Converted '1' to 1.
'       Converted '08' to 8.
'       '0F' is not in the correct format for a base 10 conversion.
'       Converted '11' to 11.
'       Converted '12' to 12.
'       Converted '30' to 30.
'       Converted '101' to 101.
'       Converted '255' to 255.
'       'FF' is not in the correct format for a base 10 conversion.
'       '10000000' is outside the range of the Byte type.
'       Converted '80' to 80.
'    Base 16:
'       '-1' is invalid in base 16.
'       Converted '1' to 1.
'       Converted '08' to 8.
'       Converted '0F' to 15.
'       Converted '11' to 17.
'       Converted '12' to 18.
'       Converted '30' to 48.
'       '101' is outside the range of the Byte type.
'       '255' is outside the range of the Byte type.
'       Converted 'FF' to 255.
'       '10000000' is outside the range of the Byte type.
'       Converted '80' to 128.

Commenti

Se fromBase è 16, è possibile anteporre al numero specificato value dal parametro "0x" o "0x".If fromBase is 16, you can prefix the number specified by the value parameter with "0x" or "0X".

Poiché il Byte tipo di dati supporta solo valori senza segno, il ToByte(String, Int32) metodo presuppone che value venga espresso utilizzando una rappresentazione binaria senza segno.Because the Byte data type supports unsigned values only, the ToByte(String, Int32) method assumes that value is expressed using unsigned binary representation. In altre parole, tutti gli otto bit vengono usati per rappresentare il valore numerico e un bit di segno è assente.In other words, all eight bits are used to represent the numeric value, and a sign bit is absent. Di conseguenza, è possibile scrivere codice in cui un valore di byte con segno non compreso nell'intervallo del tipo di Byte dati viene convertito in un Byte valore senza il metodo che genera un'eccezione.As a result, it is possible to write code in which a signed byte value that is out of the range of the Byte data type is converted to a Byte value without the method throwing an exception. Nell'esempio seguente viene MinValue convertito nella relativa rappresentazione di stringa esadecimale, quindi ToByte(String, Int32) viene chiamato il metodo.The following example converts MinValue to its hexadecimal string representation, and then calls the ToByte(String, Int32) method. Anziché generare un'eccezione, il metodo Visualizza il messaggio "0x80 converte in 128".Instead of throwing an exception, the method displays the message, "0x80 converts to 128."

// Create a hexadecimal value out of range of the Byte type.
string value = SByte.MinValue.ToString("X");
// Convert it back to a number.
try
{
   byte number = Convert.ToByte(value, 16);
   Console.WriteLine("0x{0} converts to {1}.", value, number);
}   
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a byte.", value);
}   
' Create a hexadecimal value out of range of the Byte type.
Dim value As String = SByte.MinValue.ToString("X")
' Convert it back to a number.
Try
   Dim number As Byte = Convert.ToByte(value, 16)
   Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a byte.", value)
End Try   

Quando si eseguono operazioni binarie o conversioni numeriche, è sempre responsabilità dello sviluppatore verificare che un metodo o un operatore usi la rappresentazione numerica appropriata per interpretare un determinato valore.When performing binary operations or numeric conversions, it is always the responsibility of the developer to verify that a method or operator is using the appropriate numeric representation to interpret a particular value. Nell'esempio seguente viene illustrata una tecnica per garantire che il metodo non usi in modo non appropriato la rappresentazione binaria senza segno quando converte una rappresentazione di stringa esadecimale in un Byte valore.The following example illustrates one technique for ensuring that the method does not inappropriately use unsigned binary representation when it converts a hexadecimal string representation to a Byte value. Nell'esempio viene determinato se un valore rappresenta un oggetto firmato o un Unsigned Integer durante la conversione del valore nella relativa rappresentazione di stringa.The example determines whether a value represents a signed or an unsigned integer while it is converting that value to its string representation. Quando l'esempio converte nuovamente il valore in un Byte valore, verifica se il valore originale è un intero con segno.When the example converts the value back to a Byte value, it checks whether the original value was a signed integer. In tal caso, e se viene impostato il bit più significativo (che indica che il valore è negativo e che usa il complemento a due anziché una rappresentazione binaria senza segno), il metodo genera un'eccezione.If so, and if its high-order bit is set (which indicates that the value is negative and that it uses two's complement instead of unsigned binary representation), the method throws an exception.

// Create a negative hexadecimal value out of range of the Byte type.
sbyte sourceNumber = SByte.MinValue;
bool isSigned = Math.Sign((sbyte)sourceNumber.GetType().GetField("MinValue").GetValue(null)) == -1;
string value = sourceNumber.ToString("X");
byte targetNumber;
try
{
   targetNumber = Convert.ToByte(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 an unsigned byte.", value);
} 
// Displays the following to the console:
//    Unable to convert '0x80' to an unsigned byte.     
' Create a negative hexadecimal value out of range of the Byte type.
Dim sourceNumber As SByte = SByte.MinValue
Dim isSigned As Boolean = Math.Sign(sourceNumber.MinValue) = -1
Dim value As String = sourceNumber.ToString("X")
Dim targetNumber As Byte
Try
   targetNumber = Convert.ToByte(value, 16)
   If 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 an unsigned byte.", value)
End Try 
' Displays the following to the console:
'    Unable to convert '0x80' to an unsigned byte.     

ToByte(Object, IFormatProvider) ToByte(Object, IFormatProvider) ToByte(Object, IFormatProvider) ToByte(Object, IFormatProvider)

Converte il valore dell'oggetto specificato in un intero senza segno a 8 bit mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.Converts the value of the specified object to an 8-bit unsigned integer, using the specified culture-specific formatting information.

public:
 static System::Byte ToByte(System::Object ^ value, IFormatProvider ^ provider);
public static byte ToByte (object value, IFormatProvider provider);
static member ToByte : obj * IFormatProvider -> byte
Public Shared Function ToByte (value As Object, provider As IFormatProvider) As Byte

Parametri

value
Object Object Object Object

Oggetto che implementa l'interfaccia IConvertible.An object that implements the IConvertible interface.

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

Oggetto che fornisce informazioni di formattazione specifiche delle impostazioni cultura.An object that supplies culture-specific formatting information.

Restituisce

Intero senza segno a 8 bit equivalente a value oppure zero se value è null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Eccezioni

Il formato di value non è quello della proprietà per un valore di Byte.value is not in the property format for a Byte value.

value non implementa IConvertible.value does not implement IConvertible.

-oppure--or- La conversione da value al tipo Byte non è supportata.Conversion from value to the Byte type is not supported.

L'oggetto value rappresenta un numero minore di MinValue o maggiore di MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene definita una classe ByteString che implementa l'interfaccia IConvertible .The following example defines a ByteString class that implements the IConvertible interface. La classe archivia la rappresentazione di stringa di un valore byte insieme a un campo di segno, in modo che sia in grado di rappresentare i valori di byte con segno e senza segno.The class stores the string representation of a byte value along with a sign field, so that it is able to represent both signed and unsigned byte values.

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)
   {
      if (signBit == SignBit.Negative)
         try {
            return Convert.ToSByte(Byte.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);
         }
      else   
         return SByte.Parse(byteString, NumberStyles.HexNumber);
   }

   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));
   }
}
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
      If signBit = SignBit.Positive Then
         Try
            Return Convert.ToSByte(Byte.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)), e)   
         End Try
      Else
         Return SByte.Parse(byteString, NumberStyles.HexNumber)
      End If
   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

Nell'esempio seguente viene creata un' ByteString istanza di più oggetti ToByte(Object, IFormatProvider) e viene chiamato il metodo per convertirli in valori di byte.The following example instantiates several ByteString objects and calls the ToByte(Object, IFormatProvider) method to convert them to byte values. Viene illustrato che il metodo ToByte(Object, IFormatProvider) esegue il wrapping di una chiamata IConvertible.ToByte al metodo dell'oggetto da convertire.It illustrates that the ToByte(Object, IFormatProvider) method wraps a call to the IConvertible.ToByte method of the object to be converted.

public class Class1
{
   public static void Main()
   {
      byte positiveByte = 216;
      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.ToByte(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.ToByte(negativeString));
      }
      catch (OverflowException) {
         Console.WriteLine("0x{0} is outside the range of the Byte type.", negativeString.Value);
      }   
   }
}
// The example displays the following output:
//       'D8' converts to 216.
//       0x9B is outside the range of the Byte type.
Module modMain
   Public Sub Main()
      Dim positiveByte As Byte = 216
      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.ToByte(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.ToByte(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:
'       'D8' converts to 216.
'       0x9B is outside the range of the Byte type.

Commenti

providerconsente all'utente di specificare le informazioni relative alla conversione specifiche delle impostazioni cultura valuerelative al contenuto di.provider enables the user to specify culture-specific conversion information about the contents of value. I tipi di base providerignorano; tuttavia, il parametro può essere value usato se è un tipo definito dall'utente che IConvertible implementa l'interfaccia.The base types ignore provider; however, the parameter may be used if value is a user-defined type that implements the IConvertible interface.

ToByte(String, IFormatProvider) ToByte(String, IFormatProvider) ToByte(String, IFormatProvider) ToByte(String, IFormatProvider)

Converte la rappresentazione di stringa specificata di un numero in un intero senza segno a 8 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.Converts the specified string representation of a number to an equivalent 8-bit unsigned integer, using specified culture-specific formatting information.

public:
 static System::Byte ToByte(System::String ^ value, IFormatProvider ^ provider);
public static byte ToByte (string value, IFormatProvider provider);
static member ToByte : string * IFormatProvider -> byte
Public Shared Function ToByte (value As String, provider As IFormatProvider) As Byte

Parametri

value
String String String String

Stringa che contiene il numero da convertire.A string that contains the number to convert.

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

Oggetto che fornisce informazioni di formattazione specifiche delle impostazioni cultura.An object that supplies culture-specific formatting information.

Restituisce

Intero senza segno a 8 bit equivalente a value oppure zero se value è null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Eccezioni

value non è costituito da un segno facoltativo seguito da una sequenza di cifre (da 0 a 9).value does not consist of an optional sign followed by a sequence of digits (0 through 9).

L'oggetto value rappresenta un numero minore di MinValue o maggiore di MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene creato un NumberFormatInfo oggetto personalizzato che definisce il segno positivo come "pos" e il segno negativo come "neg", utilizzato nelle chiamate ToByte(String, IFormatProvider) al metodo.The following example creates a custom NumberFormatInfo object that defines the positive sign as "pos" and the negative sign as "neg", which it uses in calls to the ToByte(String, IFormatProvider) method. Viene quindi chiamato ripetutamente il ToByte(String, IFormatProvider) metodo per convertire ogni elemento in una matrice di stringhe in un Byte valore.It then calls the ToByte(String, IFormatProvider) method repeatedly to convert each element in a string array to a Byte value.

using System;
using System.Globalization;

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

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

      // This property does not affect the conversion.
      // The input string cannot have a decimal separator.
      provider.NumberDecimalSeparator = ".";
      
      // Define an array of numeric strings.
      string[] numericStrings = { "234", "+234", "pos 234", "234.", "255", 
                                  "256", "-1" };

      foreach (string numericString in numericStrings)
      {
         Console.Write("'{0,-8}' ->   ", numericString);
         try {
            byte number = Convert.ToByte(numericString, provider);
            Console.WriteLine(number);
         }   
         catch (FormatException) {
            Console.WriteLine("Incorrect Format");
         }                             
         catch (OverflowException) {
            Console.WriteLine("Overflows a Byte");
         }   
      }
   }
}
// The example displays the following output:
//       '234     ' ->   234
//       '+234    ' ->   Incorrect Format
//       'pos 234 ' ->   234
//       '234.    ' ->   Incorrect Format
//       '255     ' ->   255
//       '256     ' ->   Overflows a Byte
//       '-1      ' ->   Incorrect Format
Imports System.Globalization

Module Example
   Public Sub Main()
      ' Create a NumberFormatInfo object and set several of its
      ' properties that apply to unsigned bytes.
      Dim provider As New NumberFormatInfo()
      With provider 
         ' These properties affect the conversion.
         .PositiveSign = "pos "
         .NegativeSign = "neg "

         ' This property does not affect the conversion.
         ' The input string cannot have a decimal separator.
         .NumberDecimalSeparator = "."
      End With
      
      ' Define an array of numeric strings.
      Dim numericStrings() As String = { "234", "+234", "pos 234", "234.", _
                                         "255", "256", "-1" }

      For Each numericString As String In numericStrings
         Console.Write("'{0,-8}' ->   ", numericString)
         Try
            Dim number As Byte = Convert.ToByte(numericString, provider)
            Console.WriteLine(number)
         Catch ex As FormatException
            Console.WriteLine("Incorrect Format")                          
         Catch ex As OverflowException
            Console.WriteLine("Overflows a Byte")
         End Try   
      Next
   End Sub   
End Module 
' The example displays the following output:
'       '234     ' ->   234
'       '+234    ' ->   Incorrect Format
'       'pos 234 ' ->   234
'       '234.    ' ->   Incorrect Format
'       '255     ' ->   255
'       '256     ' ->   Overflows a Byte
'       '-1      ' ->   Incorrect Format

Commenti

providerè un' IFormatProvider istanza di che ottiene un NumberFormatInfo oggetto.provider is an IFormatProvider instance that obtains a NumberFormatInfo object. L' NumberFormatInfo oggetto fornisce informazioni specifiche delle impostazioni cultura relative al formato valuedi.The NumberFormatInfo object provides culture-specific information about the format of value. Se provider NumberFormatInfo è null, viene utilizzato l'oggetto per le impostazioni cultura correnti.If provider is null, the NumberFormatInfo object for the current culture is used.

Se si preferisce non gestire un'eccezione se la conversione non riesce, è invece possibile chiamare Byte.TryParse il metodo.If you prefer not to handle an exception if the conversion fails, you can call the Byte.TryParse method instead. Restituisce un Boolean valore che indica se la conversione ha avuto esito positivo o negativo.It returns a Boolean value that indicates whether the conversion succeeded or failed.

Vedi anche

ToByte(Single) ToByte(Single) ToByte(Single) ToByte(Single)

Converte il valore del numero a virgola mobile a precisione singola specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified single-precision floating-point number to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(float value);
public static byte ToByte (float value);
static member ToByte : single -> byte
Public Shared Function ToByte (value As Single) As Byte

Parametri

value
Single Single Single Single

Numero a virgola mobile a precisione singola.A single-precision floating-point number.

Restituisce

value, arrotondato all'intero senza segno a 8 bit più vicino.value, rounded to the nearest 8-bit unsigned integer. Se value si trova a metà tra due numeri interi, viene restituito il numero intero pari; vale a dire, 4,5 viene convertito in 4, mentre 5,5 viene convertito in 6.If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

Eccezioni

value è maggiore di MaxValue o minore di MinValue.value is greater than MaxValue or less than MinValue.

Esempi

Nell'esempio seguente un Single valore viene convertito in un oggetto. ByteThe following example converts a Single value to a Byte.

public:
   void ConvertByteSingle( Byte byteVal )
   {
      float floatVal;
      
      // Byte to float conversion will not overflow.
      floatVal = System::Convert::ToSingle( byteVal );
      System::Console::WriteLine( "The Byte as a float is {0}.",
         floatVal );
      
      // Float to Byte conversion can overflow.
      try
      {
         byteVal = System::Convert::ToByte( floatVal );
         System::Console::WriteLine( "The float as a Byte is {0}.",
         byteVal );
      }
      catch ( System::OverflowException^ ) 
      {
         System::Console::WriteLine(
            "The float value is too large for a Byte." );
      }
   }
public void ConvertByteSingle(byte byteVal) {
    float floatVal;

    // Byte to float conversion will not overflow.
    floatVal = System.Convert.ToSingle(byteVal);
    System.Console.WriteLine("The byte as a float is {0}.",
        floatVal);

    // Float to byte conversion can overflow.
    try {
        byteVal = System.Convert.ToByte(floatVal);
        System.Console.WriteLine("The float as a byte is {0}.",
            byteVal);
    }
    catch (System.OverflowException) {
        System.Console.WriteLine(
            "The float value is too large for a byte.");
    }
}
Public Sub ConvertByteSingle(ByVal byteVal As Byte)
    Dim singleVal As Single

    ' Byte to float conversion will not overflow.
    singleVal = System.Convert.ToSingle(byteVal)
    System.Console.WriteLine("The byte as a single is {0}.", _
                              singleVal)

    ' Single to byte conversion can overflow.
    Try
        byteVal = System.Convert.ToByte(singleVal)
        System.Console.WriteLine("The single as a byte is {0}.", _
                                  byteVal)
    Catch exception As System.OverflowException
        System.Console.WriteLine( _
            "Overflow in single-to-byte conversion.")
    End Try
End Sub
Vedi anche

ToByte(UInt64) ToByte(UInt64) ToByte(UInt64) ToByte(UInt64)

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero senza segno a 64 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 64-bit unsigned integer to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(System::UInt64 value);
[System.CLSCompliant(false)]
public static byte ToByte (ulong value);
static member ToByte : uint64 -> byte
Public Shared Function ToByte (value As ULong) As Byte

Parametri

value
UInt64 UInt64 UInt64 UInt64

Intero senza segno a 64 bit da convertire.The 64-bit unsigned integer to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

Esempi

Nell'esempio seguente viene convertita una matrice di interi senza segno a Byte valori.The following example converts an array of unsigned long integers to Byte values.

ulong[] numbers= { UInt64.MinValue, 121, 340, UInt64.MaxValue };
byte result;
foreach (ulong number in numbers)
{
   try {
      result = Convert.ToByte(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 Byte type.", 
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//       Converted the UInt64 value 0 to the Byte value 0.
//       Converted the UInt64 value 121 to the Byte value 121.
//       The UInt64 value 340 is outside the range of the Byte type.
//       The UInt64 value 18446744073709551615 is outside the range of the Byte type.
Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As Byte
For Each number As ULong In numbers
   Try
      result = Convert.ToByte(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 Byte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'       Converted the UInt64 value 0 to the Byte value 0.
'       Converted the UInt64 value 121 to the Byte value 121.
'       The UInt64 value 340 is outside the range of the Byte type.
'       The UInt64 value 18446744073709551615 is outside the range of the Byte type.

ToByte(SByte) ToByte(SByte) ToByte(SByte) ToByte(SByte)

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero con segno a 8 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 8-bit signed integer to an equivalent 8-bit unsigned integer.

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

Parametri

value
SByte SByte SByte SByte

Intero con segno a 8 bit da convertire.The 8-bit signed integer to be converted.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

Esempi

Nell'esempio seguente viene convertita una SByte matrice di Byte valori in valori.The following example converts an array of SByte values to Byte values.

sbyte[] numbers = { SByte.MinValue, -1, 0, 10, SByte.MaxValue };
byte result;
foreach (sbyte number in numbers)
{
   try {
      result = Convert.ToByte(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 Byte type.", 
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//       The SByte value -128 is outside the range of the Byte type.
//       The SByte value -1 is outside the range of the Byte type.
//       Converted the SByte value 0 to the Byte value 0.
//       Converted the SByte value 10 to the Byte value 10.
//       Converted the SByte value 127 to the Byte value 127.
Dim numbers() As SByte = { SByte.MinValue, -1, 0, 10, SByte.MaxValue }
Dim result As Byte
For Each number As SByte In numbers
   Try
      result = Convert.ToByte(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 Byte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'       The SByte value -128 is outside the range of the Byte type.
'       The SByte value -1 is outside the range of the Byte type.
'       Converted the SByte value 0 to the Byte value 0.
'       Converted the SByte value 10 to the Byte value 10.
'       Converted the SByte value 127 to the Byte value 127.

ToByte(Double) ToByte(Double) ToByte(Double) ToByte(Double)

Converte il valore del numero a virgola mobile e con precisione doppia specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified double-precision floating-point number to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(double value);
public static byte ToByte (double value);
static member ToByte : double -> byte
Public Shared Function ToByte (value As Double) As Byte

Parametri

value
Double Double Double Double

Numero a virgola mobile a precisione doppia da convertire.The double-precision floating-point number to convert.

Restituisce

value, arrotondato all'intero senza segno a 8 bit più vicino.value, rounded to the nearest 8-bit unsigned integer. Se value si trova a metà tra due numeri interi, viene restituito il numero intero pari; vale a dire, 4,5 viene convertito in 4, mentre 5,5 viene convertito in 6.If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

Eccezioni

value è maggiore di MaxValue o minore di MinValue.value is greater than MaxValue or less than MinValue.

Esempi

Nell' Byte esempio seguente un valore viene convertito in un Double oggetto Double e un valore Bytein un oggetto.The following example converts a Byte value to a Double and a Double value to a Byte.

public:
   void ConvertDoubleByte( double doubleVal )
   {
      Byte byteVal = 0;
      
      // Double to Byte conversion can overflow.
      try
      {
         byteVal = System::Convert::ToByte( doubleVal );
         System::Console::WriteLine( " {0} as a Byte is: {1}.",
         doubleVal, byteVal );
      }
      catch ( System::OverflowException^ ) 
      {
         System::Console::WriteLine( "Overflow in double-to-Byte conversion." );
      }
      
      // Byte to double conversion cannot overflow.
      doubleVal = System::Convert::ToDouble( byteVal );
      System::Console::WriteLine( " {0} as a double is: {1}.",
         byteVal, doubleVal );
   }
public void ConvertDoubleByte(double doubleVal) {
    byte	byteVal = 0;

    // Double to byte conversion can overflow.
    try {
        byteVal = System.Convert.ToByte(doubleVal);
        System.Console.WriteLine("{0} as a byte is: {1}.",
            doubleVal, byteVal);
    } 
    catch (System.OverflowException) {
        System.Console.WriteLine(
            "Overflow in double-to-byte conversion.");
    }

    // Byte to double conversion cannot overflow.
    doubleVal = System.Convert.ToDouble(byteVal);
    System.Console.WriteLine("{0} as a double is: {1}.",
        byteVal, doubleVal);
}
Public Sub ConvertDoubleByte(ByVal doubleVal As Double)
    Dim byteVal As Byte = 0

    ' Double to Byte conversion can overflow.
    Try
        byteVal = System.Convert.ToByte(doubleVal)
        System.Console.WriteLine("{0} as a Byte is: {1}.", _
            doubleVal, byteVal)
    Catch exception As System.OverflowException
        System.Console.WriteLine( _
            "Overflow in Double-to-Byte conversion.")
    End Try

    ' Byte to Double conversion cannot overflow.
    doubleVal = System.Convert.ToDouble(byteVal)
    System.Console.WriteLine("{0} as a Double is: {1}.", _
                              byteVal, doubleVal)
End Sub

ToByte(Int64) ToByte(Int64) ToByte(Int64) ToByte(Int64)

Converte il valore dell'intero con segno a 64 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 64-bit signed integer to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(long value);
public static byte ToByte (long value);
static member ToByte : int64 -> byte
Public Shared Function ToByte (value As Long) As Byte

Parametri

value
Int64 Int64 Int64 Int64

Intero con segno a 64 bit da convertire.The 64-bit signed integer to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

value è minore di MinValue o maggiore di MaxValue.value is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene convertita una Int64 matrice di Byte valori in valori.The following example converts an array of Int64 values to Byte values.

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

ToByte(Byte) ToByte(Byte) ToByte(Byte) ToByte(Byte)

Restituisce l'intero senza segno a 8 bit specificato; non viene eseguita alcuna conversione effettiva.Returns the specified 8-bit unsigned integer; no actual conversion is performed.

public:
 static System::Byte ToByte(System::Byte value);
public static byte ToByte (byte value);
static member ToByte : byte -> byte
Public Shared Function ToByte (value As Byte) As Byte

Parametri

value
Byte Byte Byte Byte

Intero senza segno a 8 bit da restituire.The 8-bit unsigned integer to return.

Restituisce

value viene restituito invariato.value is returned unchanged.

ToByte(Char) ToByte(Char) ToByte(Char) ToByte(Char)

Converte il valore del carattere Unicode specificato nell'intero senza segno a 8 bit equivalente.Converts the value of the specified Unicode character to the equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(char value);
public static byte ToByte (char value);
static member ToByte : char -> byte
Public Shared Function ToByte (value As Char) As Byte

Parametri

value
Char Char Char Char

Carattere Unicode da convertire.The Unicode character to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

value rappresenta un numero maggiore di MaxValue.value represents a number that is greater than MaxValue.

Esempi

Nell'esempio seguente viene convertita una Char matrice di Byte valori in valori.The following example converts an array of Char values to Byte values.

char[] chars = { 'a', 'z', '\x0007', '\x03FF' };
foreach (char ch in chars)
{
   try {
      byte result = Convert.ToByte(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+03FF to a byte.      
Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(1023) }
For Each ch As Char in chars
   Try
      Dim result As Byte = Convert.ToByte(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+03FF to a byte.      

Commenti

Questo metodo restituisce un valore byte senza segno che rappresenta il codice numerico dell' Char oggetto passato.This method returns an unsigned byte value that represents the numeric code of the Char object passed to it. Nel .NET Framework, un Char oggetto è un valore a 16 bit.In the .NET Framework, a Char object is a 16-bit value. Questo significa che il metodo è adatto per restituire i codici numerici dei caratteri nell'intervallo di caratteri ASCII o nei controlli C0 Unicode e in latino Basic e C1 e negli intervalli di supplemento Latin-1, da U + 0000 a U + 00FF.This means that the method is suitable for returning the numeric codes of characters in the ASCII character range or in the Unicode C0 Controls and Basic Latin, and C1 Controls and Latin-1 Supplement ranges, from U+0000 to U+00FF.

ToByte(DateTime) ToByte(DateTime) ToByte(DateTime) ToByte(DateTime)

La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.Calling this method always throws InvalidCastException.

public:
 static System::Byte ToByte(DateTime value);
public static byte ToByte (DateTime value);
static member ToByte : DateTime -> byte
Public Shared Function ToByte (value As DateTime) As Byte

Parametri

value
DateTime DateTime DateTime DateTime

Valore di data e ora da convertire.The date and time value to convert.

Restituisce

Questa conversione non è supportata.This conversion is not supported. Non vengono restituiti valori.No value is returned.

Eccezioni

Questa conversione non è supportata.This conversion is not supported.

ToByte(Boolean) ToByte(Boolean) ToByte(Boolean) ToByte(Boolean)

Converte il valore booleano specificato nell'intero senza segno a 8 bit equivalente.Converts the specified Boolean value to the equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(bool value);
public static byte ToByte (bool value);
static member ToByte : bool -> byte
Public Shared Function ToByte (value As Boolean) As Byte

Parametri

value
Boolean Boolean Boolean Boolean

Valore booleano da convertire.The Boolean value to convert.

Restituisce

Il numero 1 se value è true; in caso contrario, 0.The number 1 if value is true; otherwise, 0.

Esempi

Nell'esempio seguente viene illustrata la conversione Boolean di Byte in valori.The following example illustrates the conversion of Boolean to Byte values.

using namespace System;

void main()
{
   bool falseFlag = false;
   bool trueFlag = true;

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

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

ToByte(Int16) ToByte(Int16) ToByte(Int16) ToByte(Int16)

Converte il valore dell'intero con segno a 16 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 16-bit signed integer to an equivalent 8-bit unsigned integer.

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

Parametri

value
Int16 Int16 Int16 Int16

Intero con segno a 16 bit da convertire.The 16-bit signed integer to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

value è minore di MinValue o maggiore di MaxValue.value is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene convertita una Int16 matrice di Byte valori in valori.The following example converts an array of Int16 values to Byte values.

short[] numbers = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue };
byte result;
foreach (short number in numbers)
{
   try {
      result = Convert.ToByte(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 Byte type.", 
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//       The Int16 value -32768 is outside the range of the Byte type.
//       The Int16 value -1 is outside the range of the Byte type.
//       Converted the Int16 value 0 to the Byte value 0.
//       Converted the Int16 value 121 to the Byte value 121.
//       The Int16 value 340 is outside the range of the Byte type.
//       The Int16 value 32767 is outside the range of the Byte type.
Dim numbers() As Short = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue }
Dim result As Byte
For Each number As Short In numbers
   Try
      result = Convert.ToByte(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 Byte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'       The Int16 value -32768 is outside the range of the Byte type.
'       The Int16 value -1 is outside the range of the Byte type.
'       Converted the Int16 value 0 to the Byte value 0.
'       Converted the Int16 value 121 to the Byte value 121.
'       The Int16 value 340 is outside the range of the Byte type.
'       The Int16 value 32767 is outside the range of the Byte type.

ToByte(Int32) ToByte(Int32) ToByte(Int32) ToByte(Int32)

Converte il valore dell'intero con segno a 32 bit specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified 32-bit signed integer to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(int value);
public static byte ToByte (int value);
static member ToByte : int -> byte
Public Shared Function ToByte (value As Integer) As Byte

Parametri

value
Int32 Int32 Int32 Int32

Intero con segno a 32 bit da convertire.The 32-bit signed integer to convert.

Restituisce

Intero senza segno a 8 bit equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Eccezioni

value è minore di MinValue o maggiore di MaxValue.value is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene convertita una Int32 matrice di Byte valori in valori.The following example converts an array of Int32 values to Byte values.

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

ToByte(Decimal) ToByte(Decimal) ToByte(Decimal) ToByte(Decimal)

Converte il valore del numero decimale specificato in un intero senza segno a 8 bit equivalente.Converts the value of the specified decimal number to an equivalent 8-bit unsigned integer.

public:
 static System::Byte ToByte(System::Decimal value);
public static byte ToByte (decimal value);
static member ToByte : decimal -> byte
Public Shared Function ToByte (value As Decimal) As Byte

Parametri

value
Decimal Decimal Decimal Decimal

Numero da convertire.The number to convert.

Restituisce

value, arrotondato all'intero senza segno a 8 bit più vicino.value, rounded to the nearest 8-bit unsigned integer. Se value si trova a metà tra due numeri interi, viene restituito il numero intero pari; vale a dire, 4,5 viene convertito in 4, mentre 5,5 viene convertito in 6.If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

Eccezioni

value è maggiore di MaxValue o minore di MinValue.value is greater than MaxValue or less than MinValue.

Commenti

Nell' Byte esempio seguente un valore viene convertito in un Decimal oggetto Decimal e un valore Bytein un oggetto.The following example converts a Byte value to a Decimal and a Decimal value to a Byte.

public:
   void ConvertByteDecimal( Byte byteVal )
   {
      Decimal decimalVal;
      
      // Byte to decimal conversion will not overflow.
      decimalVal = System::Convert::ToDecimal( byteVal );
      System::Console::WriteLine( "The Byte as a decimal is {0}.",
         decimalVal );
      
      // Decimal to Byte conversion can overflow.
      try
      {
         byteVal = System::Convert::ToByte( decimalVal );
         System::Console::WriteLine( "The Decimal as a Byte is {0}.",
         byteVal );
      }
      catch ( System::OverflowException^ ) 
      {
         System::Console::WriteLine(
            "The decimal value is too large for a Byte." );
      }
   }
public void ConvertByteDecimal(byte byteVal) {
    decimal decimalVal;

    // Byte to decimal conversion will not overflow.
    decimalVal = System.Convert.ToDecimal(byteVal);
    System.Console.WriteLine("The byte as a decimal is {0}.",
        decimalVal);

    // Decimal to byte conversion can overflow.
    try {
        byteVal = System.Convert.ToByte(decimalVal);
        System.Console.WriteLine("The Decimal as a byte is {0}.",
            byteVal);
    }
    catch (System.OverflowException) {
        System.Console.WriteLine(
            "The decimal value is too large for a byte.");
    }
}
Public Sub ConvertByteDecimal(ByVal byteVal As Byte)
    Dim decimalVal As Decimal

    ' Byte to decimal conversion will not overflow.
    decimalVal = System.Convert.ToDecimal(byteVal)
    System.Console.WriteLine("The byte as a decimal is {0}.", _
                              decimalVal)

    ' Decimal to byte conversion can overflow.
    Try
        byteVal = System.Convert.ToByte(decimalVal)
        System.Console.WriteLine("The Decimal as a byte is {0}.", _
                                  byteVal)
    Catch exception As System.OverflowException
        System.Console.WriteLine( _
            "Overflow in decimal-to-byte conversion.")
    End Try
End Sub

ToByte(Object) ToByte(Object) ToByte(Object) ToByte(Object)

Converte il valore dell'oggetto specificato in un intero senza segno a 8 bit.Converts the value of the specified object to an 8-bit unsigned integer.

public:
 static System::Byte ToByte(System::Object ^ value);
public static byte ToByte (object value);
static member ToByte : obj -> byte
Public Shared Function ToByte (value As Object) As Byte

Parametri

value
Object Object Object Object

Oggetto che implementa l'interfaccia IConvertible oppure null.An object that implements the IConvertible interface, or null.

Restituisce

Intero senza segno a 8 bit equivalente a value oppure zero se value è null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Eccezioni

Il formato di value non è quello della proprietà per un valore di Byte.value is not in the property format for a Byte value.

value non implementa IConvertible.value does not implement IConvertible.

-oppure--or- La conversione da value al tipo Byte non è supportata.Conversion from value to the Byte type is not supported.

L'oggetto value rappresenta un numero minore di MinValue o maggiore di MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Esempi

Nell'esempio seguente viene usato ToByte(Object) il metodo per convertire una matrice di oggetti Byte in valori.The following example uses the ToByte(Object) method to convert an array of objects to Byte values.

object[] values = { true, -12, 163, 935, 'x', "104", "103.0", "-1", 
                    "1.00e2", "One", 1.00e2};
byte result;
foreach (object value in values)
{
   try {
      result = Convert.ToByte(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 Byte 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 Byte value 1.
//       The Int32 value -12 is outside the range of the Byte type.
//       Converted the Int32 value 163 to the Byte value 163.
//       The Int32 value 935 is outside the range of the Byte type.
//       Converted the Char value x to the Byte value 120.
//       Converted the String value 104 to the Byte value 104.
//       The String value 103.0 is not in a recognizable format.
//       The String value -1 is outside the range of the Byte type.
//       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 Byte value 100.      
Dim values() As Object = { True, -12, 163, 935, "x"c, "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2}
Dim result As Byte
For Each value As Object In values
   Try
      result = Convert.ToByte(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 Byte 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 Byte value 1.
'       The Int32 value -12 is outside the range of the Byte type.
'       Converted the Int32 value 163 to the Byte value 163.
'       The Int32 value 935 is outside the range of the Byte type.
'       Converted the Char value x to the Byte value 120.
'       Converted the String value 104 to the Byte value 104.
'       The String value 103.0 is not in a recognizable format.
'       The String value -1 is outside the range of the Byte type.
'       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 Byte value 100.      

Commenti

Se value IConvertible.ToByte valuenon nullè, questo metodo esegue il wrapping di una chiamata all'implementazione del tipo sottostante di.If value is not null, this method wraps a call to the IConvertible.ToByte implementation of the underlying type of value.

Si applica a