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

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 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 (see Character Encoding in the .NET Framework for fuller explanation)

-and-

EncoderFallback is set to EncoderExceptionFallback.

To calculate the exact array size required by GetBytes to store the resulting bytes, the application uses 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.

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 UnicodeEncodingExample {
    public static void Main() {
        // Unicode characters.
        Char[] chars = new Char[] {
            '\u0023', // #
            '\u0025', // %
            '\u03a0', // Pi
            '\u03a3'  // Sigma
        };

        UnicodeEncoding Unicode = new UnicodeEncoding();
        int byteCount = Unicode.GetByteCount(chars, 1, 2);
        Console.WriteLine(
            "{0} bytes needed to encode characters.", byteCount
        );
    }
}

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

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

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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