Export (0) Print
Expand All
This topic has not yet been rated - Rate this topic

Encoding.GetByteCount Method (String)

When overridden in a derived class, calculates the number of bytes produced by encoding the characters in the specified String.

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

public virtual int GetByteCount (
	string s
)
public int GetByteCount (
	String s
)
public function GetByteCount (
	s : String
) : int
Not applicable.

Parameters

s

The String containing the set of characters to encode.

Return Value

The number of bytes produced by encoding the specified characters.
Exception typeCondition

ArgumentNullException

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

EncoderFallbackException

A fallback occurred (see Understanding Encodings for complete explanation)

-and-

EncoderFallback is set to EncoderExceptionFallback.

To calculate the exact array size required by GetBytes to store the resulting bytes, the application should use GetByteCount. To calculate the maximum array size, the application should use GetMaxByteCount. The GetByteCount method generally allows allocation of less memory, while the GetMaxByteCount method generally executes faster.

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

The following code example determines the number of bytes required to encode a string or a range in the string, 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)
      String myStr = "za\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 string, and print out the counts and the resulting bytes.
      Console.WriteLine( "Encoding the entire string:" );
      PrintCountsAndBytes( myStr, u7 );
      PrintCountsAndBytes( myStr, u8 );
      PrintCountsAndBytes( myStr, u16LE );
      PrintCountsAndBytes( myStr, u16BE );
      PrintCountsAndBytes( myStr, u32 );

      Console.WriteLine();

      // Encode three characters starting at index 4, and print out the counts and the resulting bytes.
      Console.WriteLine( "Encoding the characters from index 4 through 6:" );
      PrintCountsAndBytes( myStr, 4, 3, u7 );
      PrintCountsAndBytes( myStr, 4, 3, u8 );
      PrintCountsAndBytes( myStr, 4, 3, u16LE );
      PrintCountsAndBytes( myStr, 4, 3, u16BE );
      PrintCountsAndBytes( myStr, 4, 3, u32 );

   }


   public static void PrintCountsAndBytes( String s, Encoding enc )  {

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

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

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

      // Encode the entire string.
      byte[] bytes = enc.GetBytes( s );

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

   }


   public static void PrintCountsAndBytes( String s, 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( s.ToCharArray(), index, count );
      Console.Write( " {0,-3}", iBC );

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

      // Encode a range of characters in the string.
      byte[] bytes = new byte[iBC];
      enc.GetBytes( s, 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.

Encoding the entire string:
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

Encoding the characters from index 4 through 6:
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)
        String myStr = "za\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 the entire string, and print out the counts
        // and the resulting bytes.
        Console.WriteLine("Encoding the entire string:");
        PrintCountsAndBytes(myStr, u7);
        PrintCountsAndBytes(myStr, u8);
        PrintCountsAndBytes(myStr, u16LE);
        PrintCountsAndBytes(myStr, u16BE);
        PrintCountsAndBytes(myStr, u32);
        Console.WriteLine();

        // Encode three characters starting at index 4, 
        // and print out the counts and the resulting bytes.
        Console.WriteLine("Encoding the characters from index 4 through 6:");
        PrintCountsAndBytes(myStr, 4, 3, u7);
        PrintCountsAndBytes(myStr, 4, 3, u8);
        PrintCountsAndBytes(myStr, 4, 3, u16LE);
        PrintCountsAndBytes(myStr, 4, 3, u16BE);
        PrintCountsAndBytes(myStr, 4, 3, u32);
    } //main

    public static void PrintCountsAndBytes(String s, Encoding enc)
    {
        // Display the name of the encoding used.
        Console.Write("{0,-30} :", enc.ToString());

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

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

        // Encode the entire string.
        ubyte bytes[] = enc.GetBytes(s);

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

    public static void PrintCountsAndBytes(String s, 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(s.ToCharArray(), 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 a range of characters in the string.
        ubyte bytes[] = new ubyte[iBC];
        enc.GetBytes(s, 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.

Encoding the entire string:
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

Encoding the characters from index 4 through 6:
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 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

Community Additions

ADD
Show:
© 2014 Microsoft. All rights reserved.