Encoding.BigEndianUnicode 屬性

  • 參考

定義

命名空間:
System.Text
組件:
System.Text.Encoding.dll
組件:
System.Runtime.dll
組件:
mscorlib.dll
組件:
netstandard.dll
來源:
Encoding.cs
來源:
Encoding.cs
來源:
Encoding.cs

取得 UTF-16 格式的編碼方式，其使用由大到小的位元組順序。

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

屬性值

Encoding

UTF-16 格式的編碼物件，這個格式使用位元組由大到小的位元組順序。

範例

下列範例會使用大位元組順序來讀取具有 UTF-16 編碼的文字檔。

using namespace System;
using namespace System::IO;
int main()
{
   
   // Read a text file saved with Big Endian Unicode encoding.
   System::Text::Encoding^ encoding = System::Text::Encoding::BigEndianUnicode;
   StreamReader^ reader = gcnew StreamReader( "TextFile.txt",encoding );
   String^ line = reader->ReadLine();
   while ( line != nullptr )
   {
      Console::WriteLine( line );
      line = reader->ReadLine();
   }
}

using System;
using System.IO;

namespace BigEndianExample
{
   public class Class1 
   {
      public static void Main(string[] args) 
      {
         // Read a text file saved with Big Endian Unicode encoding.
         System.Text.Encoding encoding = System.Text.Encoding.BigEndianUnicode;
         StreamReader reader = new StreamReader("TextFile.txt", encoding);
         string line = reader.ReadLine();
         while (line != null) 
         {
            Console.WriteLine(line);
            line = reader.ReadLine();
         }
       }
    }
}

Imports System.IO

Namespace BigEndianExample
   Public Class Class1
      Public Overloads Shared Sub Main()
         ' Read a text file saved with Big Endian Unicode encoding.
         Dim encoding As System.Text.Encoding = System.Text.Encoding.BigEndianUnicode
         Dim reader As New StreamReader("TextFile.txt", encoding)
         Dim line As String = reader.ReadLine()
         While Not (line Is Nothing)
            Console.WriteLine(line)
            line = reader.ReadLine()
         End While
      End Sub
   End Class
End Namespace

下列範例會決定編碼字元陣列所需的位元組數目、編碼字元，並顯示產生的位元組。

using namespace System;
using namespace System::Text;
void PrintCountsAndBytes( array<Char>^chars, Encoding^ enc );
void PrintHexBytes( array<Byte>^bytes );
int main()
{
   
   // 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)
   //    a high-surrogate value (U+D8FF)
   //    a low-surrogate value (U+DCFF)
   array<Char>^myChars = gcnew array<Char>{
      L'z','a',L'\u0306',L'\u01FD',L'\u03B2',L'\xD8FF',L'\xDCFF'
   };
   
   // Get different encodings.
   Encoding^ u7 = Encoding::UTF7;
   Encoding^ u8 = Encoding::UTF8;
   Encoding^ u16LE = Encoding::Unicode;
   Encoding^ u16BE = Encoding::BigEndianUnicode;
   Encoding^ u32 = Encoding::UTF32;
   
   // Encode the entire array, and print out the counts and the resulting bytes.
   PrintCountsAndBytes( myChars, u7 );
   PrintCountsAndBytes( myChars, u8 );
   PrintCountsAndBytes( myChars, u16LE );
   PrintCountsAndBytes( myChars, u16BE );
   PrintCountsAndBytes( myChars, u32 );
}

void PrintCountsAndBytes( array<Char>^chars, Encoding^ enc )
{
   
   // Display the name of the encoding used.
   Console::Write( "{0,-30} :", enc );
   
   // Display the exact byte count.
   int iBC = enc->GetByteCount( chars );
   Console::Write( " {0,-3}", iBC );
   
   // Display the maximum byte count.
   int iMBC = enc->GetMaxByteCount( chars->Length );
   Console::Write( " {0,-3} :", iMBC );
   
   // Encode the array of chars.
   array<Byte>^bytes = enc->GetBytes( chars );
   
   // Display all the encoded bytes.
   PrintHexBytes( bytes );
}

void PrintHexBytes( array<Byte>^bytes )
{
   if ( (bytes == nullptr) || (bytes->Length == 0) )
      Console::WriteLine( "<none>" );
   else
   {
      for ( int i = 0; i < bytes->Length; i++ )
         Console::Write( "{0:X2} ", bytes[ i ] );
      Console::WriteLine();
   }
}

/* 
This code produces the following output.

System.Text.UTF7Encoding       : 18  23  :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding       : 12  24  :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding    : 14  16  :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding    : 14  16  :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding      : 24  32  :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00

*/

using System;
using System.Text;

public class SamplesEncoding  {

   public static void Main()  {

      // 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)
      //    a high-surrogate value (U+D8FF)
      //    a low-surrogate value (U+DCFF)
      char[] myChars = new char[] { 'z', 'a', '\u0306', '\u01FD', '\u03B2', '\uD8FF', '\uDCFF' };

      // Get different encodings.
      Encoding  u7    = Encoding.UTF7;
      Encoding  u8    = Encoding.UTF8;
      Encoding  u16LE = Encoding.Unicode;
      Encoding  u16BE = Encoding.BigEndianUnicode;
      Encoding  u32   = Encoding.UTF32;

      // Encode the entire array, and print out the counts and the resulting bytes.
      PrintCountsAndBytes( myChars, u7 );
      PrintCountsAndBytes( myChars, u8 );
      PrintCountsAndBytes( myChars, u16LE );
      PrintCountsAndBytes( myChars, u16BE );
      PrintCountsAndBytes( myChars, u32 );
   }

   public static void PrintCountsAndBytes( char[] chars, Encoding enc )  {

      // Display the name of the encoding used.
      Console.Write( "{0,-30} :", enc.ToString() );

      // Display the exact byte count.
      int iBC  = enc.GetByteCount( chars );
      Console.Write( " {0,-3}", iBC );

      // Display the maximum byte count.
      int iMBC = enc.GetMaxByteCount( chars.Length );
      Console.Write( " {0,-3} :", iMBC );

      // Encode the array of chars.
      byte[] bytes = enc.GetBytes( chars );

      // Display all the encoded bytes.
      PrintHexBytes( bytes );
   }

   public static void PrintHexBytes( byte[] bytes )  {

      if (( bytes == null ) || ( bytes.Length == 0 ))
        {
            Console.WriteLine( "<none>" );
        }
        else  {
         for ( int i = 0; i < bytes.Length; i++ )
            Console.Write( "{0:X2} ", bytes[i] );
         Console.WriteLine();
      }
   }
}


/* 
This code produces the following output.

System.Text.UTF7Encoding       : 18  23  :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
System.Text.UTF8Encoding       : 12  24  :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding    : 14  16  :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
System.Text.UnicodeEncoding    : 14  16  :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
System.Text.UTF32Encoding      : 24  32  :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00

*/

Imports System.Text

Public Class SamplesEncoding   

   Public Shared Sub Main()

      ' 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)
      '    a high-surrogate value (U+D8FF)
      '    a low-surrogate value (U+DCFF)
      Dim myChars() As Char = {"z"c, "a"c, ChrW(&H0306), ChrW(&H01FD), ChrW(&H03B2), ChrW(&HD8FF), ChrW(&HDCFF)}
 

      ' Get different encodings.
      Dim u7 As Encoding = Encoding.UTF7
      Dim u8 As Encoding = Encoding.UTF8
      Dim u16LE As Encoding = Encoding.Unicode
      Dim u16BE As Encoding = Encoding.BigEndianUnicode
      Dim u32 As Encoding = Encoding.UTF32

      ' Encode the entire array, and print out the counts and the resulting bytes.
      PrintCountsAndBytes(myChars, u7)
      PrintCountsAndBytes(myChars, u8)
      PrintCountsAndBytes(myChars, u16LE)
      PrintCountsAndBytes(myChars, u16BE)
      PrintCountsAndBytes(myChars, u32)

   End Sub


   Public Shared Sub PrintCountsAndBytes(chars() As Char, enc As Encoding)

      ' Display the name of the encoding used.
      Console.Write("{0,-30} :", enc.ToString())

      ' Display the exact byte count.
      Dim iBC As Integer = enc.GetByteCount(chars)
      Console.Write(" {0,-3}", iBC)

      ' Display the maximum byte count.
      Dim iMBC As Integer = enc.GetMaxByteCount(chars.Length)
      Console.Write(" {0,-3} :", iMBC)

      ' Encode the array of chars.
      Dim bytes As Byte() = enc.GetBytes(chars)

      ' Display all the encoded bytes.
      PrintHexBytes(bytes)

   End Sub


   Public Shared Sub PrintHexBytes(bytes() As Byte)

      If bytes Is Nothing OrElse bytes.Length = 0 Then
         Console.WriteLine("<none>")
      Else
         Dim i As Integer
         For i = 0 To bytes.Length - 1
            Console.Write("{0:X2} ", bytes(i))
         Next i
         Console.WriteLine()
      End If

   End Sub

End Class


'This code produces the following output.
'
'System.Text.UTF7Encoding       : 18  23  :7A 61 2B 41 77 59 42 2F 51 4F 79 32 50 2F 63 2F 77 2D
'System.Text.UTF8Encoding       : 12  24  :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
'System.Text.UnicodeEncoding    : 14  16  :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
'System.Text.UnicodeEncoding    : 14  16  :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
'System.Text.UTF32Encoding      : 24  32  :7A 00 00 00 61 00 00 00 06 03 00 00 FD 01 00 00 B2 03 00 00 FF FC 04 00

備註

UnicodeEncoding這個屬性所傳回的物件可能沒有適合您應用程式的行為。 它會使用取代後援來取代無法編碼的每個字串，以及無法以問號解碼的每個位元組 (「？」) 字元。 相反地，您可以呼叫 建 UnicodeEncoding.UnicodeEncoding(Boolean, Boolean, Boolean) 構函式來具現化後援為 EncoderFallbackException 或 DecoderFallbackException 的大型尾端 UnicodeEncoding 物件，如下列範例所示。

using System;
using System.Text;

public class Example
{
   public static void Main()
   {
      byte[] bytes = { 0x00, 0x20, 0xd8, 0x01, 0x00, 0x68, 0xA7, 0x00 };
      Encoding enc = new UnicodeEncoding(true, true, true);
      
      try {
         string value = enc.GetString(bytes);
         Console.WriteLine();
         Console.WriteLine("'{0}'", value);
      }
      catch (DecoderFallbackException e) {      
         Console.WriteLine("Unable to decode {0} at index {1}", 
                           ShowBytes(e.BytesUnknown), e.Index);
      }
   }

   private static string ShowBytes(byte[] bytes) 
   {
      string returnString = null;
      foreach (var byteValue in bytes)
         returnString += String.Format("0x{0:X2} ", byteValue);

      return returnString.Trim();
   }
}
// The example displays the following output:
//        Unable to decode 0xD8 0x01 at index 4

Imports System.Text

Module Example
   Public Sub Main()
      Dim bytes() As Byte = { &h00, &h20, &hd8, &h01, &h00, &h68, &hA7, &h00}
      Dim enc As Encoding = New UnicodeEncoding(True, True, True)
      
      Try
         Dim value As String = enc.GetString(bytes)
         Console.WriteLine()
         Console.WriteLine("'{0}'", value)
      Catch e As DecoderFallbackException      
         Console.WriteLine("Unable to decode {0} at index {1}", 
                           ShowBytes(e.BytesUnknown), e.Index)
      End Try
   End Sub
   
   Private Function ShowBytes(bytes As Byte()) As String
      Dim returnString As String = Nothing
      For Each byteValue In bytes
         returnString += String.Format("0x{0:X2} ", byteValue)
      Next
      Return returnString.Trim()
   End Function
End Module
' The example displays the following output:
'       Unable to decode 0xD8 0x01 at index 4

傳回 UnicodeEncoding 的物件具有 BodyName 、 HeaderName 和 WebName 屬性，其會產生名稱 「unicodeFFFE」。 雖然 UTF-16 大位元組位元組順序標記是十六進位 FEFF，但已選擇名稱 「unicodeFFFE」，因為位元組順序標記在小到小的 Windows 電腦上顯示為十六進位 FFFE。

適用於

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