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UnicodeEncoding.GetCharCount Method (Byte[], Int32, Int32)

Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array.

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

public override int GetCharCount (
	byte[] bytes,
	int index,
	int count
)
public int GetCharCount (
	byte[] bytes, 
	int index, 
	int count
)
public override function GetCharCount (
	bytes : byte[], 
	index : int, 
	count : int
) : int
Not applicable.

Parameters

bytes

The byte array containing the sequence of bytes to decode.

index

The index of the first byte to decode.

count

The number of bytes to decode.

Return Value

The number of characters produced by decoding the specified sequence of bytes.

Exception typeCondition

ArgumentNullException

bytes is a null reference (Nothing in Visual Basic)(Nothing).

ArgumentOutOfRangeException

index or count is less than zero.

-or-

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

-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 bytes contains an invalid sequence of bytes.

DecoderFallbackException

A fallback occurred (see Understanding Encodings for fuller explanation)

-and-

DecoderFallback is set to DecoderExceptionFallback.

To calculate the exact array size required by GetChars to store the resulting characters, the application uses GetCharCount. To calculate the maximum array size, the application should use GetMaxCharCount. The GetCharCount method generally allows allocation of less memory, while the GetMaxCharCount 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.

The following code example demonstrates how to use the GetCharCount method to return the number of characters produced by decoding a range of elements in a byte array using UnicodeEncoding.

using System;
using System.Text;

class UnicodeEncodingExample {
    public static void Main() {
        Byte[] bytes = new Byte[] {
            85, 0, 110, 0, 105, 0, 99, 0, 111, 0, 100, 0, 101, 0
        };

        UnicodeEncoding Unicode = new UnicodeEncoding();
        int charCount = Unicode.GetCharCount(bytes, 2, 8);
        Console.WriteLine(
            "{0} characters needed to decode bytes.", charCount
        );
    }
}

import System.*;
import System.Text.*;

class UnicodeEncodingExample
{
    public static void main(String[] args)
    {
        ubyte bytes[] = new ubyte[] { 85, 0, 110, 0, 105, 0, 99, 0, 111, 0, 
            100, 0, 101, 0 };
        UnicodeEncoding unicode = new UnicodeEncoding();
        int charCount = unicode.GetCharCount(bytes, 2, 8);
        Console.WriteLine("{0} characters needed to decode bytes.", 
            String.valueOf(charCount));
    } //main
} //UnicodeEncodingExample

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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