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

Définition

Convertit une valeur spécifiée en entier non signé 8 bits.Converts a specified value to an 8-bit unsigned integer.

Surcharges

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

Convertit la représentation sous forme de chaîne spécifiée d'un nombre en entier non signé 8 bits équivalent.Converts the specified string representation of a number to an equivalent 8-bit unsigned integer.

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

Convertit la valeur de l'entier non signé 16 bits spécifié en entier non signé 8 bits équivalent.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)

Convertit la valeur de l'entier 32 bits non signé spécifié en un entier 8 bits non signé équivalent.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)

Convertit la représentation sous forme de chaîne d'un nombre dans une base spécifiée en entier non signé 8 bits équivalent.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)

Convertit la valeur de l'objet spécifié en entier non signé 8 bits à l'aide des informations de mise en forme spécifiées propres à la culture.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)

Convertit la représentation sous forme de chaîne spécifiée d'un nombre en entier non signé 8 bits équivalent à l'aide des informations de mise en forme spécifiées propres à la culture.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)

Convertit la valeur du nombre à virgule flottante simple précision spécifié en entier non signé 8 bits équivalent.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)

Convertit la valeur de l'entier 64 bits non signé spécifié en un entier 8 bits non signé équivalent.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)

Convertit la valeur de l'entier signé 8 bits spécifié en entier non signé 8 bits équivalent.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)

Convertit la valeur du nombre à virgule flottante double précision spécifié en entier non signé 8 bits équivalent.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)

Convertit la valeur de l'entier signé 64 bits spécifié en entier non signé 8 bits équivalent.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)

Retourne l'entier non signé 8 bits spécifié. Aucune conversion n'est effectuée.Returns the specified 8-bit unsigned integer; no actual conversion is performed.

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

Convertit la valeur du caractère Unicode spécifié en entier non signé 8 bits équivalent.Converts the value of the specified Unicode character to the equivalent 8-bit unsigned integer.

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

L'appel de cette méthode lève toujours InvalidCastException.Calling this method always throws InvalidCastException.

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

Convertit la valeur booléenne spécifiée en entier non signé 8 bits équivalent.Converts the specified Boolean value to the equivalent 8-bit unsigned integer.

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

Convertit la valeur de l'entier signé 16 bits spécifié en entier non signé 8 bits équivalent.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)

Convertit la valeur de l'entier signé 32 bits spécifié en entier non signé 8 bits équivalent.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)

Convertit la valeur du nombre décimal spécifié en entier non signé 8 bits équivalent.Converts the value of the specified decimal number to an equivalent 8-bit unsigned integer.

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

Convertit la valeur de l'objet spécifié en entier non signé 8 bits.Converts the value of the specified object to an 8-bit unsigned integer.

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

Convertit la représentation sous forme de chaîne spécifiée d'un nombre en entier non signé 8 bits équivalent.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

Paramètres

value
String String String String

Chaîne contenant le nombre à convertir.A string that contains the number to convert.

Retours

Entier non signé 8 bits équivalent à value, ou zéro si value est null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceptions

value n’est pas constitué d’un signe facultatif suivi d’une séquence de chiffres (0 à 9).value does not consist of an optional sign followed by a sequence of digits (0 through 9).

value représente un nombre qui est inférieur à MinValue ou supérieur à MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Exemples

L’exemple suivant définit un tableau de chaînes et tente de convertir chaque chaîne en Byte.The following example defines a string array and attempts to convert each string to a Byte. Notez que lorsqu’une null chaîne est analysée sur zéro String.Empty , lève une FormatExceptionexception.Note that while a null string parses to zero, String.Empty throws a FormatException. Notez également que, si les espaces de début et de fin sont analysés correctement, les symboles de mise en forme, tels que les symboles monétaires, les séparateurs de groupes ou les séparateurs décimaux, ne le font pas.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

Remarques

L’utilisation ToByte(String) de la méthode équivaut à value passer à Byte.Parse(String) la méthode.Using the ToByte(String) method is equivalent to passing value to the Byte.Parse(String) method. value est interprétée à l'aide des conventions de mise en forme de la culture du thread actuel.value is interpreted by using the formatting conventions of the current thread culture.

Si vous préférez ne pas gérer une exception en cas d’échec de la conversion, vous Byte.TryParse pouvez appeler la méthode à la place.If you prefer not to handle an exception if the conversion fails, you can call the Byte.TryParse method instead. Elle retourne une Boolean valeur qui indique si la conversion a réussi ou a échoué.It returns a Boolean value that indicates whether the conversion succeeded or failed.

Voir aussi

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

Important

Cette API n’est pas conforme CLS.

Convertit la valeur de l'entier non signé 16 bits spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
UInt16 UInt16 UInt16 UInt16

Entier non signé 16 bits à convertir.The 16-bit unsigned integer to convert.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

Exemples

L’exemple suivant convertit un tableau d’entiers 16 bits non signés en Byte valeurs.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)

Important

Cette API n’est pas conforme CLS.

Convertit la valeur de l'entier 32 bits non signé spécifié en un entier 8 bits non signé équivalent.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

Paramètres

value
UInt32 UInt32 UInt32 UInt32

Entier non signé 32 bits à convertir.The 32-bit unsigned integer to convert.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

Exemples

L’exemple suivant convertit un tableau d’entiers non signés Byte en valeurs.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)

Convertit la représentation sous forme de chaîne d'un nombre dans une base spécifiée en entier non signé 8 bits équivalent.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

Paramètres

value
String String String String

Chaîne contenant le nombre à convertir.A string that contains the number to convert.

fromBase
Int32 Int32 Int32 Int32

Base du nombre figurant dans value, qui doit correspondre à 2, 8, 10 ou 16.The base of the number in value, which must be 2, 8, 10, or 16.

Retours

Entier non signé 8 bits équivalent au nombre dans value, ou 0 (zéro) si value est null.An 8-bit unsigned integer that is equivalent to the number in value, or 0 (zero) if value is null.

Exceptions

fromBase n’a pas la valeur 2, 8, 10 ou 16.fromBase is not 2, 8, 10, or 16.

- ou --or- value, qui représente un nombre non signé autre qu’en base 10, est préfixé avec un signe négatif.value, which represents a non-base 10 unsigned number, is prefixed with a negative sign.

value contient un caractère qui n’est pas un chiffre valide dans la base spécifiée par fromBase.value contains a character that is not a valid digit in the base specified by fromBase. Le message d’exception indique qu’il n’y a pas de chiffres à convertir si le premier caractère dans value n’est pas valide ; sinon, le message indique que value contient des caractères de fin non valides.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, qui représente un nombre non signé en base 10, est préfixé avec un signe négatif.value, which represents a base 10 unsigned number, is prefixed with a negative sign.

ou-or- value représente un nombre qui est inférieur à MinValue ou supérieur à MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Exemples

L’exemple suivant tente également d’interpréter un tableau de chaînes comme une représentation de valeurs binaires, octales, décimales et hexadécimales.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.

Remarques

Si fromBase a la valeur 16, vous pouvez faire précéder le value nombre spécifié par le paramètre de « 0x » ou « 0x ».If fromBase is 16, you can prefix the number specified by the value parameter with "0x" or "0X".

Étant donné Byte que le type de données ne prend en charge que ToByte(String, Int32) les valeurs non signées, la méthode suppose que value est exprimé à l’aide d’une représentation binaire non signée.Because the Byte data type supports unsigned values only, the ToByte(String, Int32) method assumes that value is expressed using unsigned binary representation. En d’autres termes, les huit bits sont utilisés pour représenter la valeur numérique et un bit de signe est absent.In other words, all eight bits are used to represent the numeric value, and a sign bit is absent. Par conséquent, il est possible d’écrire du code dans lequel une valeur d’octet signée qui est en dehors de la plage Byte du type de données est convertie en une Byte valeur sans que la méthode lève une exception.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. L’exemple suivant convertit MinValue en sa représentation sous forme de chaîne hexadécimale, puis appelle la ToByte(String, Int32) méthode.The following example converts MinValue to its hexadecimal string representation, and then calls the ToByte(String, Int32) method. Au lieu de lever une exception, la méthode affiche le message « 0x80 convertit en 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   

Lors de l’exécution d’opérations binaires ou de conversions numériques, il incombe toujours au développeur de vérifier qu’une méthode ou un opérateur utilise la représentation numérique appropriée pour interpréter une valeur particulière.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. L’exemple suivant illustre une technique permettant de s’assurer que la méthode n’utilise pas de manière inappropriée une représentation binaire non signée lorsqu’elle convertit une représentation Byte sous forme de chaîne hexadécimale en valeur.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. L’exemple détermine si une valeur représente un entier signé ou non signé pendant la conversion de cette valeur en sa représentation sous forme de chaîne.The example determines whether a value represents a signed or an unsigned integer while it is converting that value to its string representation. Lorsque l’exemple convertit la valeur en Byte valeur, il vérifie si la valeur d’origine était un entier signé.When the example converts the value back to a Byte value, it checks whether the original value was a signed integer. Si c’est le cas, et si son bit de poids fort est défini (ce qui indique que la valeur est négative et qu’elle utilise le complément à deux au lieu de la représentation binaire non signée), la méthode lève une exception.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)

Convertit la valeur de l'objet spécifié en entier non signé 8 bits à l'aide des informations de mise en forme spécifiées propres à la culture.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

Paramètres

value
Object Object Object Object

Objet qui implémente l'interface IConvertible.An object that implements the IConvertible interface.

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

Objet qui fournit des informations de mise en forme propres à la culture.An object that supplies culture-specific formatting information.

Retours

Entier non signé 8 bits équivalent à value, ou zéro si value est null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceptions

value n’a pas le format de propriété pour une valeur Byte.value is not in the property format for a Byte value.

value n’implémente pas IConvertible.value does not implement IConvertible.

ou-or- La conversion de value en type Byte n’est pas prise en charge.Conversion from value to the Byte type is not supported.

value représente un nombre qui est inférieur à MinValue ou supérieur à MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Exemples

L'exemple suivant définit une classe ByteString qui implémente l'interface IConvertible .The following example defines a ByteString class that implements the IConvertible interface. La classe stocke la représentation sous forme de chaîne d’une valeur d’octet avec un champ de signe, afin qu’elle puisse représenter des valeurs d’octets signés et non signés.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

L’exemple suivant instancie plusieurs ByteString objets et appelle la ToByte(Object, IFormatProvider) méthode pour les convertir en valeurs d’octets.The following example instantiates several ByteString objects and calls the ToByte(Object, IFormatProvider) method to convert them to byte values. Il montre que la ToByte(Object, IFormatProvider) méthode encapsule un appel à la IConvertible.ToByte méthode de l’objet à convertir.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.

Remarques

providerpermet à l’utilisateur de spécifier des informations de conversion spécifiques à la culture valueconcernant le contenu de.provider enables the user to specify culture-specific conversion information about the contents of value. Les types de base providerignorent ; Toutefois, le paramètre peut être value utilisé si est un type défini par l’utilisateur qui IConvertible implémente l’interface.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)

Convertit la représentation sous forme de chaîne spécifiée d'un nombre en entier non signé 8 bits équivalent à l'aide des informations de mise en forme spécifiées propres à la culture.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

Paramètres

value
String String String String

Chaîne contenant le nombre à convertir.A string that contains the number to convert.

provider
IFormatProvider IFormatProvider IFormatProvider IFormatProvider

Objet qui fournit des informations de mise en forme propres à la culture.An object that supplies culture-specific formatting information.

Retours

Entier non signé 8 bits équivalent à value, ou zéro si value est null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceptions

value n’est pas constitué d’un signe facultatif suivi d’une séquence de chiffres (0 à 9).value does not consist of an optional sign followed by a sequence of digits (0 through 9).

value représente un nombre qui est inférieur à MinValue ou supérieur à MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Exemples

L’exemple suivant crée un objet NumberFormatInfo personnalisé qui définit le signe positif comme « POS » et le signe négatif comme « nég », qu’il utilise dans les appels à ToByte(String, IFormatProvider) la méthode.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. Il appelle ensuite la ToByte(String, IFormatProvider) méthode à plusieurs reprises pour convertir chaque élément d’un tableau de chaînes Byte en une valeur.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

Remarques

providerest une IFormatProvider instance qui obtient un NumberFormatInfo objet.provider is an IFormatProvider instance that obtains a NumberFormatInfo object. L' NumberFormatInfo objet fournit des informations spécifiques à la culture sur le valueformat de.The NumberFormatInfo object provides culture-specific information about the format of value. Si provider est null, l'NumberFormatInfo objet pour la culture actuelle est utilisé.If provider is null, the NumberFormatInfo object for the current culture is used.

Si vous préférez ne pas gérer une exception en cas d’échec de la conversion, vous Byte.TryParse pouvez appeler la méthode à la place.If you prefer not to handle an exception if the conversion fails, you can call the Byte.TryParse method instead. Elle retourne une Boolean valeur qui indique si la conversion a réussi ou a échoué.It returns a Boolean value that indicates whether the conversion succeeded or failed.

Voir aussi

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

Convertit la valeur du nombre à virgule flottante simple précision spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
Single Single Single Single

Nombre à virgule flottante simple précision.A single-precision floating-point number.

Retours

value, arrondi à l’entier non signé 8 bits le plus proche.value, rounded to the nearest 8-bit unsigned integer. Si value se trouve entre deux nombres entiers, le nombre pair est retourné (par exemple, 4,5 est converti en 4 et 5,5 en 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.

Exceptions

value est supérieur à MaxValue ou inférieur à MinValue.value is greater than MaxValue or less than MinValue.

Exemples

L’exemple suivant convertit Single une valeur Byteen.The 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
Voir aussi

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

Important

Cette API n’est pas conforme CLS.

Convertit la valeur de l'entier 64 bits non signé spécifié en un entier 8 bits non signé équivalent.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

Paramètres

value
UInt64 UInt64 UInt64 UInt64

Entier non signé 64 bits à convertir.The 64-bit unsigned integer to convert.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

Exemples

L’exemple suivant convertit un tableau d’entiers longs non signés Byte en valeurs.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)

Important

Cette API n’est pas conforme CLS.

Convertit la valeur de l'entier signé 8 bits spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
SByte SByte SByte SByte

Entier signé 8 bits à convertir.The 8-bit signed integer to be converted.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

Exemples

L’exemple suivant convertit un tableau SByte de valeurs Byte en valeurs.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)

Convertit la valeur du nombre à virgule flottante double précision spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
Double Double Double Double

Nombre à virgule flottante double précision à convertir.The double-precision floating-point number to convert.

Retours

value, arrondi à l’entier non signé 8 bits le plus proche.value, rounded to the nearest 8-bit unsigned integer. Si value se trouve entre deux nombres entiers, le nombre pair est retourné (par exemple, 4,5 est converti en 4 et 5,5 en 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.

Exceptions

value est supérieur à MaxValue ou inférieur à MinValue.value is greater than MaxValue or less than MinValue.

Exemples

L’exemple suivant convertit Byte une valeur Double en Byteet une Double valeur en.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)

Convertit la valeur de l'entier signé 64 bits spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
Int64 Int64 Int64 Int64

Entier signé 64 bits à convertir.The 64-bit signed integer to convert.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

value est inférieur à MinValue ou supérieur à MaxValue.value is less than MinValue or greater than MaxValue.

Exemples

L’exemple suivant convertit un tableau Int64 de valeurs Byte en valeurs.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)

Retourne l'entier non signé 8 bits spécifié. Aucune conversion n'est effectuée.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

Paramètres

value
Byte Byte Byte Byte

Entier non signé 8 bits à retourner.The 8-bit unsigned integer to return.

Retours

value est retourné sans modification.value is returned unchanged.

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

Convertit la valeur du caractère Unicode spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
Char Char Char Char

Caractère Unicode à convertir.The Unicode character to convert.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

value représente un nombre supérieur à MaxValue.value represents a number that is greater than MaxValue.

Exemples

L’exemple suivant convertit un tableau Char de valeurs Byte en valeurs.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.      

Remarques

Cette méthode retourne une valeur d’octet non signée qui représente le code numérique de l' Char objet qui lui est passé.This method returns an unsigned byte value that represents the numeric code of the Char object passed to it. Dans le .NET Framework, un Char objet est une valeur de 16 bits.In the .NET Framework, a Char object is a 16-bit value. Cela signifie que la méthode convient pour retourner les codes numériques de caractères de la plage de caractères ASCII ou des contrôles C0 Unicode et latin de base, ainsi que les contrôles C1 et les plages de suppléments latin-1, entre U + 0000 et 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)

L'appel de cette méthode lève toujours 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

Paramètres

value
DateTime DateTime DateTime DateTime

Valeur de date et heure à convertir.The date and time value to convert.

Retours

Cette conversion n'est pas prise en charge.This conversion is not supported. Aucune valeur n'est retournée.No value is returned.

Exceptions

Cette conversion n'est pas prise en charge.This conversion is not supported.

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

Convertit la valeur booléenne spécifiée en entier non signé 8 bits équivalent.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

Paramètres

value
Boolean Boolean Boolean Boolean

Valeur booléenne à convertir.The Boolean value to convert.

Retours

Chiffre 1, si value est true ; sinon, 0.The number 1 if value is true; otherwise, 0.

Exemples

L’exemple suivant illustre la conversion de Boolean en Byte valeurs.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)

Convertit la valeur de l'entier signé 16 bits spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
Int16 Int16 Int16 Int16

Entier signé 16 bits à convertir.The 16-bit signed integer to convert.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

value est inférieur à MinValue ou supérieur à MaxValue.value is less than MinValue or greater than MaxValue.

Exemples

L’exemple suivant convertit un tableau Int16 de valeurs Byte en valeurs.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)

Convertit la valeur de l'entier signé 32 bits spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
Int32 Int32 Int32 Int32

Entier signé 32 bits à convertir.The 32-bit signed integer to convert.

Retours

Entier non signé 8 bits équivalent à value.An 8-bit unsigned integer that is equivalent to value.

Exceptions

value est inférieur à MinValue ou supérieur à MaxValue.value is less than MinValue or greater than MaxValue.

Exemples

L’exemple suivant convertit un tableau Int32 de valeurs Byte en valeurs.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)

Convertit la valeur du nombre décimal spécifié en entier non signé 8 bits équivalent.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

Paramètres

value
Decimal Decimal Decimal Decimal

Nombre à convertir.The number to convert.

Retours

value, arrondi à l’entier non signé 8 bits le plus proche.value, rounded to the nearest 8-bit unsigned integer. Si value se trouve entre deux nombres entiers, le nombre pair est retourné (par exemple, 4,5 est converti en 4 et 5,5 en 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.

Exceptions

value est supérieur à MaxValue ou inférieur à MinValue.value is greater than MaxValue or less than MinValue.

Remarques

L’exemple suivant convertit Byte une valeur Decimal en Byteet une Decimal valeur en.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)

Convertit la valeur de l'objet spécifié en entier non signé 8 bits.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

Paramètres

value
Object Object Object Object

Objet qui implémente l'interface IConvertible ou null.An object that implements the IConvertible interface, or null.

Retours

Entier non signé 8 bits équivalent à value, ou zéro si value est null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceptions

value n’a pas le format de propriété pour une valeur Byte.value is not in the property format for a Byte value.

value n’implémente pas IConvertible.value does not implement IConvertible.

- ou --or- La conversion de value en type Byte n’est pas prise en charge.Conversion from value to the Byte type is not supported.

value représente un nombre qui est inférieur à MinValue ou supérieur à MaxValue.value represents a number that is less than MinValue or greater than MaxValue.

Exemples

L’exemple suivant utilise la ToByte(Object) méthode pour convertir un tableau d’objets en Byte valeurs.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.      

Remarques

Si value n’a nullpas la valeur, cette méthode encapsule un IConvertible.ToByte appel à l’implémentation du type valuesous-jacent de.If value is not null, this method wraps a call to the IConvertible.ToByte implementation of the underlying type of value.

S’applique à