Export (0) Print
Expand All

Encoding.GetBytes Method (Char[], Int32, Int32)

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

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

public virtual byte[] GetBytes (
	char[] chars,
	int index,
	int count
)
public byte[] GetBytes (
	char[] chars, 
	int index, 
	int count
)
public function GetBytes (
	chars : char[], 
	index : int, 
	count : int
) : byte[]

Parameters

chars

The character array containing the set of characters to encode.

index

The index of the first character to encode.

count

The number of characters to encode.

Return Value

A byte array containing the results of encoding the specified set of characters.

Exception typeCondition

ArgumentNullException

chars 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 chars.

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, use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.

The following code example determines the number of bytes required to encode three characters from a character array, encodes the characters, and displays the resulting bytes.

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 three characters starting at index 4, and print out the counts and the resulting bytes.
      PrintCountsAndBytes( myChars, 4, 3, u7 );
      PrintCountsAndBytes( myChars, 4, 3, u8 );
      PrintCountsAndBytes( myChars, 4, 3, u16LE );
      PrintCountsAndBytes( myChars, 4, 3, u16BE );
      PrintCountsAndBytes( myChars, 4, 3, u32 );

   }


   public static void PrintCountsAndBytes( char[] chars, int index, int count, 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, index, count );
      Console.Write( " {0,-3}", iBC );

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

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

      // The following is an alternative way to encode the array of chars:
      // byte[] bytes = new byte[iBC];
      // enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) );

      // 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       : 10  11  :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding       : 6   12  :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding    : 6   8   :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding    : 6   8   :03 B2 D8 FF DC FF
System.Text.UTF32Encoding      : 8   16  :B2 03 00 00 FF FC 04 00

*/


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

public class SamplesEncoding
{
    public static void main(String[] args)
    {
        // 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.get_UTF7();
        Encoding u8 = Encoding.get_UTF8();
        Encoding u16LE = Encoding.get_Unicode();
        Encoding u16BE = Encoding.get_BigEndianUnicode();
        Encoding u32 = Encoding.get_UTF32();

        // Encode three characters starting at index 4, 
        // and print out the counts and the resulting bytes.
        PrintCountsAndBytes(myChars, 4, 3, u7);
        PrintCountsAndBytes(myChars, 4, 3, u8);
        PrintCountsAndBytes(myChars, 4, 3, u16LE);
        PrintCountsAndBytes(myChars, 4, 3, u16BE);
        PrintCountsAndBytes(myChars, 4, 3, u32);
    } //main

    public static void PrintCountsAndBytes(char chars[], int index,
                                            int count, 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, index, count);
        Console.Write(" {0,-3}", String.valueOf(iBC));

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

        // Encode the array of chars.
        ubyte bytes[] = enc.GetBytes(chars, index, count);

        // The following is an alternative way to encode the array of chars:
        // byte[] bytes = new byte[iBC];
        // enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) );
        // Display all the encoded bytes.
        PrintHexBytes(bytes);
    } //PrintCountsAndBytes

    public static void PrintHexBytes(ubyte bytes[])
    {
        if(bytes == null || bytes.length == 0) {
            Console.WriteLine("<none>");
        }
        else {
            for(int i = 0; i < bytes.length; i++) {
                Console.Write("{0:X2} ",
                        ((System.Byte)bytes[i]).ToString("X2"));
            }
            Console.WriteLine();
        }
    } //PrintHexBytes
} //SamplesEncoding

/* 
This code produces the following output.

System.Text.UTF7Encoding       : 10  11  :2B 41 37 4C 59 2F 39 7A 2F 2D
System.Text.UTF8Encoding       : 6   12  :CE B2 F1 8F B3 BF
System.Text.UnicodeEncoding    : 6   8   :B2 03 FF D8 FF DC
System.Text.UnicodeEncoding    : 6   8   :03 B2 D8 FF DC FF
System.Text.UTF32Encoding      : 8   16  :B2 03 00 00 FF FC 04 00

*/


Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

Community Additions

ADD
Show:
© 2014 Microsoft