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Encoding.GetChars Method (Byte[], Int32, Int32)

When overridden in a derived class, decodes a sequence of bytes from the specified byte array into a set of characters.

Namespace: System.Text
Assembly: mscorlib (in mscorlib.dll)

public virtual char[] GetChars (
	byte[] bytes,
	int index,
	int count
)
public char[] GetChars (
	byte[] bytes, 
	int index, 
	int count
)
public function GetChars (
	bytes : byte[], 
	index : int, 
	count : int
) : char[]
Not applicable.

Parameters

bytes
index
count

Return Value

A character array containing the results of decoding the specified sequence of bytes.

Exception typeCondition

ArgumentNullException

bytes is a null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

index or count is less than zero.

-or-

index and count do not denote a valid range in bytes.

DecoderFallbackException

A fallback occurred (see Understanding Encodings for complete explanation)

-and-

DecoderFallback is set to DecoderExceptionFallback.

If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, the application should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.

Note   This method is intended to operate on Unicode characters, not on arbitrary binary data, such as byte arrays. If your application needs to encode arbitrary binary data into text, it should use a protocol such as uuencode, which is implemented by methods such as System.Convert.ToBase64CharArray.

For a discussion of programming considerations for use of this method, see the Encoding class description.

The following code example encodes a string into an array of bytes, and then decodes a range of the bytes into an array of characters.

using System;
using System.Text;

public class SamplesEncoding  {

   public static void Main()  {

      // Create two instances of UTF32Encoding: one with little-endian byte order and one with big-endian byte order.
      Encoding u32LE = Encoding.GetEncoding( "utf-32" );
      Encoding u32BE = Encoding.GetEncoding( "utf-32BE" );

      // Use a 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)
      String myStr = "za\u0306\u01FD\u03B2";

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

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

      // Get the char counts, decode eight bytes starting at index 0,
      // and print out the counts and the resulting bytes.
      Console.Write( "BE array with BE encoding : " );
      PrintCountsAndChars( barrBE, 0, 8, u32BE );
      Console.Write( "LE array with LE encoding : " );
      PrintCountsAndChars( barrLE, 0, 8, u32LE );

   }


   public static void PrintCountsAndChars( byte[] bytes, int index, int count, 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, index, count );
      Console.Write( " {0,-3}", iCC );

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

      // Decode the bytes and display the characters.
      char[] chars = enc.GetChars( bytes, index, count );

      // The following is an alternative way to decode the bytes:
      // char[] chars = new char[iCC];
      // enc.GetChars( bytes, index, count, chars, 0 );

      Console.WriteLine( chars );

   }

}


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

BE array with BE encoding : System.Text.UTF32Encoding : 2   6   :za
LE array with LE encoding : System.Text.UTF32Encoding : 2   6   :za

*/


import System.*;
import System.Text.*;

public class SamplesEncoding
{
    public static void main(String[] args)
    {
        // Create two instances of UTF32Encoding: one with little-endian 
        // byte order and one with big-endian byte order.
        Encoding u32LE = Encoding.GetEncoding("utf-32");
        Encoding u32BE = Encoding.GetEncoding("utf-32BE");

        // Use a 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)
        String myStr = "za\u0306\u01FD\u03B2";

        // Encode the string using the big-endian byte order.
        ubyte barrBE[] = new ubyte[u32BE.GetByteCount(myStr)];
        u32BE.GetBytes(myStr, 0, myStr.get_Length(), barrBE, 0);

        // Encode the string using the little-endian byte order.
        ubyte barrLE[] = new ubyte[u32LE.GetByteCount(myStr)];
        u32LE.GetBytes(myStr, 0, myStr.get_Length(), barrLE, 0);

        // Get the char counts, decode eight bytes starting at index 0,
        // and print out the counts and the resulting bytes.
        Console.Write("BE array with BE encoding : ");
        PrintCountsAndChars(barrBE, 0, 8, u32BE);
        Console.Write("LE array with LE encoding : ");
        PrintCountsAndChars(barrLE, 0, 8, u32LE);
    } //main

    public static void PrintCountsAndChars(ubyte bytes[], 
                    int index, int count, 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, index, count);
        Console.Write(" {0,-3}", String.valueOf(iCC));

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

        // Decode the bytes and display the characters.
        char chars[] = enc.GetChars(bytes, index, count);

        // The following is an alternative way to decode the bytes:
        // char[] chars = new char[iCC];
        // enc.GetChars( bytes, index, count, chars, 0 );
        Console.WriteLine(chars);
    } //PrintCountsAndChars
} //SamplesEncoding

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

BE array with BE encoding : System.Text.UTF32Encoding : 2   6   :za
LE array with LE encoding : System.Text.UTF32Encoding : 2   6   :za

*/


Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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