UTF32Encoding.GetChars 方法

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

public:
 override int GetChars(System::Byte* bytes, int byteCount, char* chars, int charCount);

[System.CLSCompliant(false)]
[System.Security.SecurityCritical]
public override int GetChars(byte* bytes, int byteCount, char* chars, int charCount);

[System.CLSCompliant(false)]
public override int GetChars(byte* bytes, int byteCount, char* chars, int charCount);

[<System.CLSCompliant(false)>]
[<System.Security.SecurityCritical>]
override this.GetChars : nativeptr<byte> * int * nativeptr<char> * int -> int

[<System.CLSCompliant(false)>]
override this.GetChars : nativeptr<byte> * int * nativeptr<char> * int -> int

參數

傳回

在 所示 chars位置書寫的實際字元數。

屬性

CLSCompliantAttribute SecurityCriticalAttribute

例外狀況

備註

要計算儲存所得字元所需的 GetChars 精確陣列大小，請呼叫該 GetCharCount 方法。 要計算最大陣列大小，請呼叫該 GetMaxCharCount 方法。 此 GetCharCount 方法通常分配較少記憶體，而 GetMaxCharCount 執行速度較快。

在錯誤檢測中，若序列無效，該方法會拋出 ArgumentException。 若無錯誤偵測，無效序列會被忽略，且不會拋出例外。

若解碼的位元組範圍包含位元組順序標記（BOM），且位元組陣列是由非 BOM 識別型態的方法回傳，則字元 U+FFFE 會包含在該方法回傳的字元陣列中。 你可以透過呼叫 String.TrimStart 該方法來移除它。

待轉換的資料，例如從串流讀取的資料，可能只能以連續區塊形式取得。 在這種情況下，或資料量龐大到需要分割成較小區塊時，應用程式會分別使用Decoder方法或Encoder方法所提供的 GetDecoder 或 GetEncoder 。

另請參閱

• GetCharCount(Byte[], Int32, Int32)
• GetMaxCharCount(Int32)
• GetDecoder()
• GetString(Byte[], Int32, Int32)

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

來源:

UTF32Encoding.cs

public:
 override int GetChars(cli::array <System::Byte> ^ bytes, int byteIndex, int byteCount, cli::array <char> ^ chars, int charIndex);

public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex);

override this.GetChars : byte[] * int * int * char[] * int -> int

Public Overrides Function GetChars (bytes As Byte(), byteIndex As Integer, byteCount As Integer, chars As Char(), charIndex As Integer) As Integer

參數

傳回

實際寫入 chars的字元數。

例外狀況

範例

以下範例將字串編碼成一個位元組陣列，然後將位元組解碼成一個字元陣列。

using System;
using System.Text;

public class SamplesUTF32Encoding  {

   public static void Main()  {

      // Create two instances of UTF32Encoding: one with little-endian byte order and one with big-endian byte order.
      UTF32Encoding u32LE = new UTF32Encoding( false, true, true );
      UTF32Encoding u32BE = new UTF32Encoding( true, true, true );

      // Create byte arrays from the same string containing the following characters:
      //    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)
      String myStr = "za\u0306\u01FD\u03B2\uD8FF\uDCFF";

      // barrBE uses the big-endian byte order.
      byte[] barrBE = new byte[u32BE.GetByteCount( myStr )];
      u32BE.GetBytes( myStr, 0, myStr.Length, barrBE, 0 );

      // barrLE uses the little-endian byte order.
      byte[] barrLE = new byte[u32LE.GetByteCount( myStr )];
      u32LE.GetBytes( myStr, 0, myStr.Length, barrLE, 0 );

      // Get the char counts and decode the byte arrays.
      Console.Write( "BE array with BE encoding : " );
      PrintCountsAndChars( barrBE, u32BE );
      Console.Write( "LE array with LE encoding : " );
      PrintCountsAndChars( barrLE, u32LE );

      // Decode the byte arrays using an encoding with a different byte order.
      Console.Write( "BE array with LE encoding : " );
      try  {
         PrintCountsAndChars( barrBE, u32LE );
      }
      catch ( System.ArgumentException e )  {
         Console.WriteLine( e.Message );
      }

      Console.Write( "LE array with BE encoding : " );
      try  {
         PrintCountsAndChars( barrLE, u32BE );
      }
      catch ( System.ArgumentException e )  {
         Console.WriteLine( e.Message );
      }
   }

   public static void PrintCountsAndChars( byte[] bytes, Encoding enc )  {

      // Display the name of the encoding used.
      Console.Write( "{0,-25} :", enc.ToString() );

      // Display the exact character count.
      int iCC  = enc.GetCharCount( bytes );
      Console.Write( " {0,-3}", iCC );

      // Display the maximum character count.
      int iMCC = enc.GetMaxCharCount( bytes.Length );
      Console.Write( " {0,-3} :", iMCC );

      // Decode the bytes and display the characters.
      char[] chars = new char[iCC];
      enc.GetChars( bytes, 0, bytes.Length, chars, 0 );
      Console.WriteLine( chars );
   }
}

Imports System.Text

Public Class SamplesUTF32Encoding   

   Public Shared Sub Main()

      ' Create two instances of UTF32Encoding: one with little-endian byte order and one with big-endian byte order.
      Dim u32LE As New UTF32Encoding(False, True, True)
      Dim u32BE As New UTF32Encoding(True, True, True)


      ' Create byte arrays from the same string containing the following characters:
      '    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 myStr As String = "za" & ChrW(&H0306) & ChrW(&H01FD) & ChrW(&H03B2) & ChrW(&HD8FF) & ChrW(&HDCFF)

      ' barrBE uses the big-endian byte order.
      ' 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 barrBE(u32BE.GetByteCount(myStr) - 1) As Byte
      u32BE.GetBytes(myStr, 0, myStr.Length, barrBE, 0)

      ' barrLE uses the little-endian byte order.
      ' 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 barrLE(u32LE.GetByteCount(myStr) - 1) As Byte
      u32LE.GetBytes(myStr, 0, myStr.Length, barrLE, 0)


      ' Get the char counts and decode the byte arrays.
      Console.Write("BE array with BE encoding : ")
      PrintCountsAndChars(barrBE, u32BE)
      Console.Write("LE array with LE encoding : ")
      PrintCountsAndChars(barrLE, u32LE)


      ' Decode the byte arrays using an encoding with a different byte order.
      Console.Write("BE array with LE encoding : ")
      Try
         PrintCountsAndChars(barrBE, u32LE)
      Catch e As System.ArgumentException
         Console.WriteLine(e.Message)
      End Try

      Console.Write("LE array with BE encoding : ")
      Try
         PrintCountsAndChars(barrLE, u32BE)
      Catch e As System.ArgumentException
         Console.WriteLine(e.Message)
      End Try

   End Sub


   Public Shared Sub PrintCountsAndChars(bytes() As Byte, enc As Encoding)

      ' Display the name of the encoding used.
      Console.Write("{0,-25} :", enc.ToString())

      ' Display the exact character count.
      Dim iCC As Integer = enc.GetCharCount(bytes)
      Console.Write(" {0,-3}", iCC)

      ' Display the maximum character count.
      Dim iMCC As Integer = enc.GetMaxCharCount(bytes.Length)
      Console.Write(" {0,-3} :", iMCC)

      ' Decode the bytes and display the characters.
      Dim chars(iCC) As Char
      enc.GetChars(bytes, 0, bytes.Length, chars, 0)
      Console.WriteLine(chars)

   End Sub

End Class

備註

要計算儲存所得字元所需的 GetChars 精確陣列大小，請呼叫該 GetCharCount 方法。 要計算最大陣列大小，請呼叫該 GetMaxCharCount 方法。 此 GetCharCount 方法通常分配較少記憶體，而 GetMaxCharCount 執行速度較快。

在錯誤檢測中，若序列無效，該方法會拋出 ArgumentException。 若無錯誤偵測，無效序列會被忽略，且不會拋出例外。

若解碼的位元組範圍包含位元組順序標記（BOM），且位元組陣列是由非 BOM 識別型態的方法回傳，則字元 U+FFFE 會包含在該方法回傳的字元陣列中。 你可以透過呼叫 String.TrimStart 該方法來移除它。

待轉換的資料，例如從串流讀取的資料，可能只能以連續區塊形式取得。 在這種情況下，或資料量龐大到需要分割成較小區塊時，應用程式會分別使用Decoder方法或Encoder方法所提供的 GetDecoder 或 GetEncoder 。

另請參閱

• GetCharCount(Byte[], Int32, Int32)
• GetMaxCharCount(Int32)
• GetDecoder()
• GetString(Byte[], Int32, Int32)