通过

UnicodeEncoding.GetDecoder 方法

定义

命名空间:
System.Text
程序集:
mscorlib.dll, System.Text.Encoding.Extensions.dll
程序集:
netstandard.dll, System.Text.Encoding.Extensions.dll
程序集:
System.Text.Encoding.Extensions.dll
程序集:
mscorlib.dll
程序集:
netstandard.dll
Source:
UnicodeEncoding.cs
Source:
UnicodeEncoding.cs
Source:
UnicodeEncoding.cs
Source:
UnicodeEncoding.cs

获取可以将 UTF-16 编码的字节序列转换为 Unicode 字符序列的解码器。

public:
 override System::Text::Decoder ^ GetDecoder();
public override System.Text.Decoder GetDecoder();
override this.GetDecoder : unit -> System.Text.Decoder
Public Overrides Function GetDecoder () As Decoder

返回

Decoder

一个 Decoder，用于将 UTF-16 编码的字节序列转换为 Unicode 字符序列。

示例

以下示例使用编码器和解码器将字符串编码为字节数组，然后将字节解码为字符数组。

using System;
using System.Text;

public class SamplesUnicodeEncoding  {

   public static void Main()  {

      // Get an encoder and a decoder from UnicodeEncoding.
      UnicodeEncoding u16 = new UnicodeEncoding( false, true, true );
      Encoder myEnc = u16.GetEncoder();
      Decoder myDec = u16.GetDecoder();

      // The characters to encode:
      //    Latin Small Letter Z (U+007A)
      //    Latin Small Letter A (U+0061)
      //    Combining Breve (U+0306)
      //    Latin Small Letter AE With Acute (U+01FD)
      //    Greek Small Letter Beta (U+03B2)
      char[] myChars = new char[5] { 'z', 'a', '\u0306', '\u01FD', '\u03B2' };
      Console.Write( "The original characters : " );
      Console.WriteLine( myChars );

      // Encode the character array.
      int iBC  = myEnc.GetByteCount( myChars, 0, myChars.Length, true );
      byte[] myBytes = new byte[iBC];
      myEnc.GetBytes( myChars, 0, myChars.Length, myBytes, 0, true );

      // Print the resulting bytes.
      Console.Write( "Using the encoder       : " );
      for ( int i = 0; i < myBytes.Length; i++ )
         Console.Write( "{0:X2} ", myBytes[i] );
      Console.WriteLine();

      // Decode the byte array back into an array of characters.
      int iCC  = myDec.GetCharCount( myBytes, 0, myBytes.Length, true );
      char[] myDecodedChars = new char[iCC];
      myDec.GetChars( myBytes, 0, myBytes.Length, myDecodedChars, 0, true );

      // Print the resulting characters.
      Console.Write( "Using the decoder       : " );
      Console.WriteLine( myDecodedChars );
   }
}


/* 
This code produces the following output.  The question marks take the place of characters that cannot be displayed at the console.

The original characters : za??ß
Using the encoder       : 7A 00 61 00 06 03 FD 01 B2 03
Using the decoder       : za??ß

*/

Imports System.Text

Public Class SamplesUnicodeEncoding   

   Public Shared Sub Main()

      ' Get an encoder and a decoder from UnicodeEncoding.
      Dim u16 As New UnicodeEncoding(False, True, True)
      Dim myEnc As Encoder = u16.GetEncoder()
      Dim myDec As Decoder = u16.GetDecoder()

      ' The characters to encode:
      '    Latin Small Letter Z (U+007A)
      '    Latin Small Letter A (U+0061)
      '    Combining Breve (U+0306)
      '    Latin Small Letter AE With Acute (U+01FD)
      '    Greek Small Letter Beta (U+03B2)
      Dim myChars() As Char = {"z"c, "a"c, ChrW(&H0306), ChrW(&H01FD), ChrW(&H03B2)}
      Console.Write("The original characters : ")
      Console.WriteLine(myChars)

      ' Encode the character array.
      Dim iBC As Integer = myEnc.GetByteCount(myChars, 0, myChars.Length, True)
      ' NOTE: In Visual Basic, arrays contain one extra element by default.
      '       The following line creates an array with the exact number of elements required.
      Dim myBytes(iBC - 1) As Byte
      myEnc.GetBytes(myChars, 0, myChars.Length, myBytes, 0, True)

      ' Print the resulting bytes.
      Console.Write("Using the encoder       : ")
      Dim i As Integer
      For i = 0 To myBytes.Length - 1
         Console.Write("{0:X2} ", myBytes(i))
      Next i
      Console.WriteLine()

      ' Decode the byte array back into an array of characters.
      Dim iCC As Integer = myDec.GetCharCount(myBytes, 0, myBytes.Length, True)
      ' NOTE: In Visual Basic, arrays contain one extra element by default.
      '       The following line creates an array with the exact number of elements required.
      Dim myDecodedChars(iCC - 1) As Char
      myDec.GetChars(myBytes, 0, myBytes.Length, myDecodedChars, 0, True)

      ' Print the resulting characters.
      Console.Write("Using the decoder       : ")
      Console.WriteLine(myDecodedChars)

   End Sub

End Class


'This code produces the following output.  The question marks take the place of characters that cannot be displayed at the console.
'
'The original characters : za??ß
'Using the encoder       : 7A 00 61 00 06 03 FD 01 B2 03
'Using the decoder       : za??ß

注解

方法 Decoder.GetChars 以类似于 GetChars的方式将连续字节块转换为连续字符块。 但是， 在 Decoder 调用之间维护状态信息，以便它可以正确解码跨块的字节序列。 Decoder还保留数据块末尾的尾随字节，并在下一个解码操作中使用尾随字节。 因此， GetDecoder 和 GetEncoder 对于网络传输和文件操作非常有用，因为这些操作经常处理数据块而不是完整的数据流。

如果启用了错误检测，即 throwOnInvalidBytes 构造函数的参数设置为 true，也会在此方法返回的 中 Decoder 启用错误检测。 如果启用错误检测并遇到无效序列，则解码器的状态为未定义且必须停止处理。

适用于

另请参阅