Convert.ToByte Método

public:
 static System::Byte ToByte(System::String ^ value);

public static byte ToByte (string value);

public static byte ToByte (string? value);

static member ToByte : string -> byte

Public Shared Function ToByte (value As String) As Byte

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value, ou zero caso value seja null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceções

Exemplos

O exemplo a seguir define uma matriz de cadeia de caracteres e tenta converter cada cadeia de caracteres em um Byte .The following example defines a string array and attempts to convert each string to a Byte. Observe que, enquanto uma null cadeia de caracteres é analisada como zero, String.Empty o lança um FormatException .Note that while a null string parses to zero, String.Empty throws a FormatException. Observe também que, enquanto os espaços à esquerda e à direita são analisados com êxito, a formatação de símbolos, como símbolos de moeda, separadores de grupo ou separadores decimais, não.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

Comentários

O uso do ToByte(String) método é equivalente ao passar value para o Byte.Parse(String) método.Using the ToByte(String) method is equivalent to passing value to the Byte.Parse(String) method. value é interpretado usando as convenções de formatação da cultura de thread atual.value is interpreted by using the formatting conventions of the current thread culture.

Se você preferir não tratar uma exceção se a conversão falhar, você poderá chamar o Byte.TryParse método em vez disso.If you prefer not to handle an exception if the conversion fails, you can call the Byte.TryParse method instead. Ele retorna um valor Boolean que indica se a conversão foi bem-sucedida ou falhou.It returns a Boolean value that indicates whether the conversion succeeded or failed.

Confira também

• Parse(String)

public:
 static System::Byte ToByte(System::UInt16 value);

[System.CLSCompliant(false)]
public static byte ToByte (ushort value);

[<System.CLSCompliant(false)>]
static member ToByte : uint16 -> byte

Public Shared Function ToByte (value As UShort) As Byte

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Atributos

CLSCompliantAttribute

Exceções

Exemplos

O exemplo a seguir converte uma matriz de inteiros de 16 bits não assinados em Byte valores.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.

public:
 static System::Byte ToByte(System::UInt32 value);

[System.CLSCompliant(false)]
public static byte ToByte (uint value);

[<System.CLSCompliant(false)>]
static member ToByte : uint32 -> byte

Public Shared Function ToByte (value As UInteger) As Byte

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Atributos

CLSCompliantAttribute

Exceções

Exemplos

O exemplo a seguir converte uma matriz de inteiros não assinados em Byte valores.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.

public:
 static System::Byte ToByte(System::String ^ value, int fromBase);

public static byte ToByte (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

Parâmetros

Retornos

Byte

Um inteiro sem sinal de 8 bits equivalente ao número em value, ou 0 (zero), se value for null.An 8-bit unsigned integer that is equivalent to the number in value, or 0 (zero) if value is null.

Exceções

Exemplos

O exemplo a seguir tenta interpretar uma matriz de cadeias de caracteres como a representação dos valores binary, octal, decimal e hexadecimal.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.

Comentários

Caso fromBase seja 16, é possível prefixar o número especificado pelo parâmetro value com "0x" ou "0X".If fromBase is 16, you can prefix the number specified by the value parameter with "0x" or "0X".

Como o Byte tipo de dados dá suporte apenas a valores não assinados, o ToByte(String, Int32) método pressupõe que value é expresso usando uma representação binária não assinada.Because the Byte data type supports unsigned values only, the ToByte(String, Int32) method assumes that value is expressed using unsigned binary representation. Em outras palavras, todos os oito bits são usados para representar o valor numérico e um bit de sinal está ausente.In other words, all eight bits are used to represent the numeric value, and a sign bit is absent. Como resultado, é possível escrever código no qual um valor de byte assinado que está fora do intervalo do Byte tipo de dados é convertido em um Byte valor sem que o método emita uma exceção.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. O exemplo a seguir converte MinValue em sua representação de cadeia de caracteres hexadecimal e, em seguida, chama o ToByte(String, Int32) método.The following example converts MinValue to its hexadecimal string representation, and then calls the ToByte(String, Int32) method. Em vez de lançar uma exceção, o método exibe a mensagem "0x80 converte para 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   

Durante a realização de operações binárias ou conversões numéricas, sempre é responsabilidade do desenvolvedor verificar se um método ou operador está usando a representação numérica apropriada para interpretar um valor específico.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. O exemplo a seguir ilustra uma técnica para garantir que o método não use inadequadamente a representação binária não assinada ao converter uma representação de cadeia de caracteres hexadecimal em um Byte valor.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. O exemplo determina se um valor representa um inteiro assinado ou não assinado enquanto converte esse valor na representação da cadeia de caracteres.The example determines whether a value represents a signed or an unsigned integer while it is converting that value to its string representation. Quando o exemplo converte o valor de volta para um Byte valor, ele verifica se o valor original era um inteiro assinado.When the example converts the value back to a Byte value, it checks whether the original value was a signed integer. Nesse caso, e se seu bit de ordem superior for definido (o que indica que o valor é negativo e que usa o complemento de dois, em vez de uma representação binária não assinada), o método gera uma exceção.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.     

public:
 static System::Byte ToByte(System::Object ^ value, IFormatProvider ^ provider);

public static byte ToByte (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

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value, ou zero caso value seja null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceções

Exemplos

O exemplo a seguir define uma classe ByteString que implementa a interface IConvertible.The following example defines a ByteString class that implements the IConvertible interface. A classe armazena a representação de cadeia de caracteres de um valor de byte junto com um campo de sinal, para que seja capaz de representar valores de bytes assinados e não assinados.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

O exemplo a seguir instancia vários ByteString objetos e chama o ToByte(Object, IFormatProvider) método para convertê-los em valores de bytes.The following example instantiates several ByteString objects and calls the ToByte(Object, IFormatProvider) method to convert them to byte values. Ele ilustra que o ToByte(Object, IFormatProvider) método encapsula uma chamada para o IConvertible.ToByte método do objeto a ser convertido.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.

Comentários

provider permite que o usuário especifique informações de conversão específicas de cultura sobre o conteúdo de value .provider enables the user to specify culture-specific conversion information about the contents of value. Os tipos de base ignoram provider; no entanto, o parâmetro pode ser usado caso value seja um tipo definido pelo usuário que implementa a interface IConvertible.The base types ignore provider; however, the parameter may be used if value is a user-defined type that implements the IConvertible interface.

public:
 static System::Byte ToByte(System::String ^ value, IFormatProvider ^ provider);

public static byte ToByte (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

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value, ou zero caso value seja null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceções

Exemplos

O exemplo a seguir cria um NumberFormatInfo objeto personalizado que define o sinal positivo como "PDV" e o sinal negativo como "neg", que ele usa em chamadas para o ToByte(String, IFormatProvider) método.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. Em seguida, ele chama o ToByte(String, IFormatProvider) método repetidamente para converter cada elemento em uma matriz de cadeia de caracteres em um Byte valor.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

Comentários

provider é uma IFormatProvider instância que obtém um NumberFormatInfo objeto.provider is an IFormatProvider instance that obtains a NumberFormatInfo object. O objeto NumberFormatInfo fornece informações específicas da cultura sobre o formato de value.The NumberFormatInfo object provides culture-specific information about the format of value. Caso provider seja null, o objeto NumberFormatInfo da cultura atual é usado.If provider is null, the NumberFormatInfo object for the current culture is used.

Se você preferir não tratar uma exceção se a conversão falhar, você poderá chamar o Byte.TryParse método em vez disso.If you prefer not to handle an exception if the conversion fails, you can call the Byte.TryParse method instead. Ele retorna um valor Boolean que indica se a conversão foi bem-sucedida ou falhou.It returns a Boolean value that indicates whether the conversion succeeded or failed.

Confira também

• Parse(String)

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

Parâmetros

Retornos

Byte

value, arredondado para o próximo inteiro sem sinal de 8 bits.value, rounded to the nearest 8-bit unsigned integer. Caso value esteja entre dois números inteiros, o número par é retornado; ou seja, 4,5 é convertido em 4 e 5,5 é convertido em 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.

Exceções

Exemplos

O exemplo a seguir converte um Single valor em um Byte .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

Confira também

• Round

public:
 static System::Byte ToByte(System::UInt64 value);

[System.CLSCompliant(false)]
public static byte ToByte (ulong value);

[<System.CLSCompliant(false)>]
static member ToByte : uint64 -> byte

Public Shared Function ToByte (value As ULong) As Byte

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Atributos

CLSCompliantAttribute

Exceções

Exemplos

O exemplo a seguir converte uma matriz de inteiros longos sem sinal em Byte valores.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.

public:
 static System::Byte ToByte(System::SByte value);

[System.CLSCompliant(false)]
public static byte ToByte (sbyte value);

[<System.CLSCompliant(false)>]
static member ToByte : sbyte -> byte

Public Shared Function ToByte (value As SByte) As Byte

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Atributos

CLSCompliantAttribute

Exceções

Exemplos

O exemplo a seguir converte uma matriz de SByte valores em Byte valores.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.

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

Parâmetros

Retornos

Byte

value, arredondado para o próximo inteiro sem sinal de 8 bits.value, rounded to the nearest 8-bit unsigned integer. Caso value esteja entre dois números inteiros, o número par é retornado; ou seja, 4,5 é convertido em 4 e 5,5 é convertido em 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.

Exceções

Comentários

O exemplo a seguir converte um Byte valor em um Decimal e um Decimal valor para um Byte .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

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

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Exceções

Exemplos

O exemplo a seguir converte uma matriz de Int64 valores em Byte valores.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.      

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

Parâmetros

Retornos

Byte

value é retornado inalterado.value is returned unchanged.

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

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Exceções

Exemplos

O exemplo a seguir converte uma matriz de Char valores em Byte valores.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.      

Comentários

Esse método retorna um valor de byte não assinado que representa o código numérico do Char objeto passado para ele.This method returns an unsigned byte value that represents the numeric code of the Char object passed to it. No .NET, um Char objeto é um valor de 16 bits.In .NET, a Char object is a 16-bit value. Isso significa que o método é adequado para retornar os códigos numéricos de caracteres no intervalo de caracteres ASCII ou nos controles de C0 Unicode e nos controles latinos, e latim, e nos intervalos de suplementos latino-1, de U + 0000 a U + 00FF.This means that the method is suitable for returning the numeric codes of characters in the ASCII character range or in the Unicode C0 Controls and Basic Latin, and C1 Controls and Latin-1 Supplement ranges, from U+0000 to U+00FF.

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

Parâmetros

Retornos

Byte

Não há suporte para esta conversão.This conversion is not supported. Nenhum valor é retornado.No value is returned.

Exceções

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

Parâmetros

Retornos

Byte

O número 1 caso value seja true; do contrário, 0.The number 1 if value is true; otherwise, 0.

Exemplos

O exemplo a seguir ilustra a conversão de Boolean para Byte valores.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.

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

Parâmetros

Retornos

Byte

value, arredondado para o próximo inteiro sem sinal de 8 bits.value, rounded to the nearest 8-bit unsigned integer. Caso value esteja entre dois números inteiros, o número par é retornado; ou seja, 4,5 é convertido em 4 e 5,5 é convertido em 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.

Exceções

Exemplos

O exemplo a seguir converte um Byte valor em um Double e um Double valor para um Byte .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

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

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Exceções

Exemplos

O exemplo a seguir converte uma matriz de Int16 valores em Byte valores.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.

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

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value.An 8-bit unsigned integer that is equivalent to value.

Exceções

Exemplos

O exemplo a seguir converte uma matriz de Int32 valores em Byte valores.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.      

public:
 static System::Byte ToByte(System::Object ^ value);

public static byte ToByte (object value);

public static byte ToByte (object? value);

static member ToByte : obj -> byte

Public Shared Function ToByte (value As Object) As Byte

Parâmetros

Retornos

Byte

Um inteiro não assinado de 8 bits equivalente a value, ou zero caso value seja null.An 8-bit unsigned integer that is equivalent to value, or zero if value is null.

Exceções

Exemplos

O exemplo a seguir usa o ToByte(Object) método para converter uma matriz de objetos em Byte valores.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.      

Comentários

Se value não for null , esse método encapsula uma chamada para a IConvertible.ToByte implementação do tipo subjacente de value .If value is not null, this method wraps a call to the IConvertible.ToByte implementation of the underlying type of value.