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Encoder.GetByteCount Method (Char[], Int32, Int32, Boolean)

When overridden in a derived class, calculates the number of bytes produced by encoding a set of characters from the specified character array. A parameter indicates whether to clear the internal state of the encoder after the calculation.

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

public abstract int GetByteCount(
	char[] chars,
	int index,
	int count,
	bool flush
)

Parameters

chars
Type: System.Char[]
The character array containing the set of characters to encode.
index
Type: System.Int32
The zero-based index of the first character to encode.
count
Type: System.Int32
The number of characters to encode.
flush
Type: System.Boolean
true to simulate clearing the internal state of the encoder after the calculation; otherwise, false.

Return Value

Type: System.Int32
The number of bytes produced by encoding the specified characters and any characters in the internal buffer.

ExceptionCondition
ArgumentNullException

chars is null.

ArgumentOutOfRangeException

index or count is less than zero.

-or-

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

EncoderFallbackException

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

This method does not affect the state of the encoder.

The GetByteCount(Char[], Int32, Int32, Boolean) method calculates the exact array size that the GetBytes method requires to store the encoded bytes.

If GetBytes is called with flush set to false, the encoder stores trailing characters at the end of the data block in an internal buffer and uses them in the next encoding operation. The application should call GetByteCount on a block of data immediately before calling GetBytes on the same block, so that any trailing characters from the previous block are included in the calculation.

The following code example demonstrates how to use the GetByteCount method to return the number of bytes required to encode an array of characters using a Unicode Encoder.


using System;
using System.Text;

class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      // Unicode characters.
      Char[] chars = new Char[] {
            '\u0023', // #
            '\u0025', // %
            '\u03a0', // Pi
            '\u03a3'  // Sigma
        };

      Encoder uniEncoder = Encoding.Unicode.GetEncoder();
      int byteCount = uniEncoder.GetByteCount(chars, 0, chars.Length, true);
      outputBlock.Text += String.Format(
          "{0} bytes needed to encode characters.", byteCount
      ) + "\n";
   }
}


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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