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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
)

Parameters

s
Type: System.String
The string that contains the set of characters to encode.

Return Value

Type: System.Int32
The number of bytes produced by encoding the specified characters.
ExceptionCondition
ArgumentNullException

s is null.

EncoderFallbackException

A fallback occurred (see Understanding Encodings for complete explanation).

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 allocates 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 Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      // 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 u8 = Encoding.UTF8;
      Encoding u16LE = Encoding.Unicode;
      Encoding u16BE = Encoding.BigEndianUnicode;

      // Encode the entire string, and print out the counts and the resulting bytes.
      outputBlock.Text += "Encoding the entire string:\n";
      PrintCountsAndBytes(outputBlock, myStr, u8);
      PrintCountsAndBytes(outputBlock, myStr, u16LE);
      PrintCountsAndBytes(outputBlock, myStr, u16BE);

      outputBlock.Text += "\n";

      // Encode three characters starting at index 4, and print out the counts and the resulting bytes.
      outputBlock.Text += "Encoding the characters from index 4 through 6:\n";
      PrintCountsAndBytes(outputBlock, myStr, 4, 3, u8);
      PrintCountsAndBytes(outputBlock, myStr, 4, 3, u16LE);
      PrintCountsAndBytes(outputBlock, myStr, 4, 3, u16BE);
   }

   public static void PrintCountsAndBytes(System.Windows.Controls.TextBlock outputBlock, 
                                          String s, Encoding enc)
   {
      // Display the name of the encoding used.
      outputBlock.Text += String.Format("{0,-30} :", enc.ToString());

      // Display the exact byte count.
      int iBC = enc.GetByteCount(s);
      outputBlock.Text += String.Format(" {0,-3}", iBC);

      // Display the maximum byte count.
      int iMBC = enc.GetMaxByteCount(s.Length);
      outputBlock.Text += String.Format(" {0,-3} :", iMBC);

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

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

   public static void PrintCountsAndBytes(System.Windows.Controls.TextBlock outputBlock, 
                                          String s, int index, int count, Encoding enc)
   {
      // Display the name of the encoding used.
      outputBlock.Text += String.Format("{0,-30} :", enc.ToString());

      // Display the exact byte count.
      int iBC = enc.GetByteCount(s.ToCharArray(), index, count);
      outputBlock.Text += String.Format(" {0,-3}", iBC);

      // Display the maximum byte count.
      int iMBC = enc.GetMaxByteCount(count);
      outputBlock.Text += String.Format(" {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(outputBlock, bytes);
   }

   public static void PrintHexBytes(System.Windows.Controls.TextBlock outputBlock, 
                                    byte[] bytes)
   {
      if ((bytes == null) || (bytes.Length == 0))
         outputBlock.Text += "<none>" + "\n";
      else
      {
         for (int i = 0; i < bytes.Length; i++)
            outputBlock.Text += String.Format("{0:X2} ", bytes[i]);
         outputBlock.Text += "\n";
      }
   }
}
/* 
This example produces the following output.

Encoding the entire string:
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

Encoding the characters from index 4 through 6:
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
*/


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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