Encoding.UTF8 Encoding.UTF8 Encoding.UTF8 Encoding.UTF8 Property

Definición

Obtiene una codificación para el formato UTF-8.Gets an encoding for the UTF-8 format.

public:
 static property System::Text::Encoding ^ UTF8 { System::Text::Encoding ^ get(); };
public static System.Text.Encoding UTF8 { get; }
member this.UTF8 : System.Text.Encoding
Public Shared ReadOnly Property UTF8 As Encoding

Valor de propiedad

Codificación para el formato UTF-8.An encoding for the UTF-8 format.

Ejemplos

El ejemplo siguiente define una matriz que consta de los siguientes caracteres:The following example defines an array that consists of the following characters:

  • LETRA MINÚSCULA LATINA Z (007A)LATIN SMALL LETTER Z (U+007A)

  • LETRA LATINA MINÚSCULA UN (U+0061)LATIN SMALL LETTER A (U+0061)

  • COMBINACIÓN CORTA (0306)COMBINING BREVE (U+0306)

  • LETRA LATINA MINÚSCULA AE CON AGUDA (U + 01FD)LATIN SMALL LETTER AE WITH ACUTE (U+01FD)

  • LETRA GRIEGA BETA (03B2)GREEK SMALL LETTER BETA (U+03B2)

  • Un par suplente (U+D800 U + DD54) que los formularios GRIEGA ACROPHONIC ATTIC uno MILES STATERS (10154).A surrogate pair (U+D800 U+DD54) that forms GREEK ACROPHONIC ATTIC ONE THOUSAND STATERS (U+10154).

Muestra las unidades de código UTF-16 de cada carácter y determina el número de bytes requeridos por un codificador UTF-8 para codificar la matriz de caracteres.It displays the UTF-16 code units of each character and determines the number of bytes required by a UTF-8 encoder to encode the character array. A continuación, se codifica los caracteres y se muestran los bytes resultantes codificado en UTF-8.It then encodes the characters and displays the resulting UTF-8-encoded bytes.

using System;
using System.Text;

public class Example
{
   public static void Main()  
   {
      // Create a character array.
      string gkNumber = Char.ConvertFromUtf32(0x10154);
      char[] chars = new char[] { 'z', 'a', '\u0306', '\u01FD', '\u03B2', 
                                  gkNumber[0], gkNumber[1] };

      // Get UTF-8 and UTF-16 encoders.
      Encoding utf8 = Encoding.UTF8;
      Encoding utf16 = Encoding.Unicode;
      
      // Display the original characters' code units.
      Console.WriteLine("Original UTF-16 code units:");
      byte[] utf16Bytes = utf16.GetBytes(chars);
      foreach (var utf16Byte in utf16Bytes)
         Console.Write("{0:X2} ", utf16Byte);
      Console.WriteLine();
         
      // Display the number of bytes required to encode the array.
      int reqBytes  = utf8.GetByteCount(chars);
      Console.WriteLine("\nExact number of bytes required: {0}", 
                    reqBytes);

      // Display the maximum byte count.
      int maxBytes = utf8.GetMaxByteCount(chars.Length);
      Console.WriteLine("Maximum number of bytes required: {0}\n", 
                        maxBytes);

      // Encode the array of chars.
      byte[] utf8Bytes = utf8.GetBytes(chars);

      // Display all the UTF-8-encoded bytes.
      Console.WriteLine("UTF-8-encoded code units:");
      foreach (var utf8Byte in utf8Bytes)
         Console.Write("{0:X2} ", utf8Byte);
      Console.WriteLine();
   }
}
// The example displays the following output:
//       Original UTF-16 code units:
//       7A 00 61 00 06 03 FD 01 B2 03 00 D8 54 DD
//       
//       Exact number of bytes required: 12
//       Maximum number of bytes required: 24
//       
//       UTF-8-encoded code units:
//       7A 61 CC 86 C7 BD CE B2 F0 90 85 94
Imports System.Text

Public Module Example
   Public Sub Main()
      ' Create a character array.
      Dim gkNumber As String = Char.ConvertFromUtf32(&h10154)
      Dim chars() As Char = {"z"c, "a"c, ChrW(&H0306), ChrW(&H01FD), 
                             ChrW(&H03B2), gkNumber(0), gkNumber(1) }
 
      ' Get UTF-8 and UTF-16 encoders.
      Dim utf8 As Encoding = Encoding.UTF8
      Dim utf16 As Encoding = Encoding.Unicode

      ' Display the original characters' code units.
      Console.WriteLine("Original UTF-16 code units:")
      Dim utf16Bytes() As Byte = utf16.GetBytes(chars)
      For Each utf16Byte In utf16Bytes
         Console.Write("{0:X2} ", utf16Byte)
      Next
      Console.WriteLine()

      Console.WriteLine()
      ' Display the number of bytes required to encode the array.
      Dim reqBytes As Integer = utf8.GetByteCount(chars)
      Console.WriteLine("Exact number of bytes required: {0}", 
                        reqBytes)

      ' Display the maximum byte count.
      Dim maxBytes As Integer = utf8.GetMaxByteCount(chars.Length)
      Console.WriteLine("Maximum number of bytes required: {0}", 
                        maxBytes)
      Console.WriteLine()
      
      ' Encode the array of characters.
      Dim utf8Bytes() As Byte = utf8.GetBytes(chars)

      ' Display all the UTF-8-encoded bytes.
      Console.WriteLine("UTF-8-encoded code units:")
      For Each utf8Byte In utf8Bytes
         Console.Write("{0:X2} ", utf8Byte)
      Next
      Console.WriteLine()
   End Sub 
End Module 
' The example displays the following output:
'    Original UTF-16 code units:
'    7A 00 61 00 06 03 FD 01 B2 03 00 D8 54 DD
'    
'    Exact number of bytes required: 12
'    Maximum number of bytes required: 24
'    
'    UTF-8-encoded code units:
'    7A 61 CC 86 C7 BD CE B2 F0 90 85 94

Comentarios

Esta propiedad devuelve un UTF8Encoding objeto que codifica los caracteres de Unicode (UTF-16-codificada) en una secuencia de uno a cuatro bytes por carácter, y que descodifica una matriz de bytes codificada en UTF-8 a Unicode (UTF-16-codificada) caracteres.This property returns a UTF8Encoding object that encodes Unicode (UTF-16-encoded) characters into a sequence of one to four bytes per character, and that decodes a UTF-8-encoded byte array to Unicode (UTF-16-encoded) characters. Para obtener información acerca de las codificaciones de caracteres compatibles con .NET y una explicación de qué codificación Unicode para usar, vea codificación de caracteres en .NET.For information about the character encodings supported by .NET and a discussion of which Unicode encoding to use, see Character Encoding in .NET.

La UTF8Encoding objeto devuelto por esta propiedad puede no tener el comportamiento adecuado para la aplicación.The UTF8Encoding object that is returned by this property might not have the appropriate behavior for your app.

  • Devuelve un UTF8Encoding objeto que proporciona una marca de orden de bytes Unicode (BOM).It returns a UTF8Encoding object that provides a Unicode byte order mark (BOM). Para crear una instancia de una codificación UTF8 que no proporciona una lista de materiales, llamar a ninguna sobrecarga de la UTF8Encoding constructor.To instantiate a UTF8 encoding that doesn't provide a BOM, call any overload of the UTF8Encoding constructor.

  • Devuelve un UTF8Encoding objeto que usa la reserva de reemplazo para reemplazar cada cadena que no se puede codificar y cada byte que no se puede descodificar con un signo de interrogación ("?") caracteres.It returns a UTF8Encoding object that uses replacement fallback to replace each string that it can't encode and each byte that it can't decode with a question mark ("?") character. En su lugar, puede llamar a la UTF8Encoding.UTF8Encoding(Boolean, Boolean) constructor para crear instancias de un UTF8Encoding objeto cuya reserva sea un EncoderFallbackException o un DecoderFallbackException, tal y como se muestra en el ejemplo siguiente.Instead, you can call the UTF8Encoding.UTF8Encoding(Boolean, Boolean) constructor to instantiate a UTF8Encoding object whose fallback is either an EncoderFallbackException or a DecoderFallbackException, as the following example illustrates.

    using System;
    using System.Text;
    
    public class Example
    {
       public static void Main()
       {
          Encoding enc = new UTF8Encoding(true, true);
          string value = "\u00C4 \uD802\u0033 \u00AE"; 
    
          try {
             byte[] bytes= enc.GetBytes(value);
             foreach (var byt in bytes)
                Console.Write("{0:X2} ", byt);
             Console.WriteLine();
    
             string value2 = enc.GetString(bytes);
             Console.WriteLine(value2);
          }
          catch (EncoderFallbackException e) {
             Console.WriteLine("Unable to encode {0} at index {1}", 
                               e.IsUnknownSurrogate() ? 
                                  String.Format("U+{0:X4} U+{1:X4}", 
                                                Convert.ToUInt16(e.CharUnknownHigh),
                                                Convert.ToUInt16(e.CharUnknownLow)) :
                                  String.Format("U+{0:X4}", 
                                                Convert.ToUInt16(e.CharUnknown)),
                               e.Index);
          }                     
       }
    }
    // The example displays the following output:
    //        Unable to encode U+D802 at index 2
    
    Imports System.Text
    
    Module Example
       Public Sub Main()
          Dim enc As Encoding = New UTF8Encoding(True, True)
          Dim value As String = String.Format("{0} {1}{2} {3}", 
                                ChrW(&h00C4), ChrW(&hD802), ChrW(&h0033), ChrW(&h00AE))
          
          Try
             Dim bytes() As Byte = enc.GetBytes(value)
             For Each byt As Byte In bytes
                Console.Write("{0:X2} ", byt)
             Next       
             Console.WriteLine()
             Dim value2 As String = enc.GetString(bytes)
             Console.WriteLine(value2)
          Catch e As EncoderFallbackException
             Console.WriteLine("Unable to encode {0} at index {1}", 
                               If(e.IsUnknownSurrogate(), 
                                  String.Format("U+{0:X4} U+{1:X4}", 
                                                Convert.ToUInt16(e.CharUnknownHigh),
                                                Convert.ToUInt16(e.CharUnknownLow)),
                                  String.Format("U+{0:X4}", 
                                                Convert.ToUInt16(e.CharUnknown))),
                               e.Index)
          End Try
       End Sub
    End Module
    ' The example displays the following output:
    '       Unable to encode U+D802 at index 2
    

Se aplica a

Consulte también: