UnicodeEncoding.GetByteCount Method (Char[], Int32, Int32)

May 11, 2014

Calculates the number of bytes produced by encoding a set of characters from the specified character array.

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

public override int GetByteCount(
	char[] chars,
	int index,
	int count
)

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.

Return Value

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

ExceptionCondition
ArgumentNullException

chars is null (Nothing).

ArgumentOutOfRangeException

index or count is less than zero.

-or-

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

-or-

The resulting number of bytes is greater than the maximum number that can be returned as an integer.

ArgumentException

Error detection is enabled, and chars contains an invalid sequence of characters.

EncoderFallbackException

A fallback occurred.

To calculate the exact array size required by GetBytes to store the resulting bytes, call the GetByteCount method. To calculate the maximum array size, call the GetMaxByteCount method. The GetByteCount method generally allocates less memory, while the GetMaxByteCount method generally executes faster.

With error detection, an invalid sequence causes this method to throw a ArgumentException. Without error detection, invalid sequences are ignored, and no exception is thrown.

NoteNote:

To ensure that the encoded bytes are decoded properly, the application should prefix encoded bytes with a preamble.

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


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
        };

      UnicodeEncoding Unicode = new UnicodeEncoding();
      int byteCount = Unicode.GetByteCount(chars, 1, 2);
      outputBlock.Text += String.Format(
          "{0} bytes needed to encode characters.", byteCount
      ) + "\n";
   }
}


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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