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
Assemblies:   mscorlib (in mscorlib.dll)
  System.Text.Encoding (in System.Text.Encoding.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 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 Character Encoding in the .NET Framework for fuller explanation)

-and-

Fallback is set to EncoderExceptionFallback.

This method does not affect the state of the encoder.

To calculate the exact array size that GetBytes requires to store the resulting bytes, the application should use GetByteCount.

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 EncoderExample {
    public static void Main() {
        // 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);
        Console.WriteLine(
            "{0} bytes needed to encode characters.", byteCount
        );
    }
}

/* This example produces the following output.

8 bytes needed to encode characters.

*/

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2015 Microsoft