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UnicodeEncoding.GetBytes Method (String, Int32, Int32, Byte[], Int32)

Encodes a set of characters from the specified String into the specified byte array.

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

public override int GetBytes (
	string s,
	int charIndex,
	int charCount,
	byte[] bytes,
	int byteIndex
public int GetBytes (
	String s, 
	int charIndex, 
	int charCount, 
	byte[] bytes, 
	int byteIndex
public override function GetBytes (
	s : String, 
	charIndex : int, 
	charCount : int, 
	bytes : byte[], 
	byteIndex : int
) : int



The String containing the set of characters to encode.


The index of the first character to encode.


The number of characters to encode.


The byte array to contain the resulting sequence of bytes.


The index at which to start writing the resulting sequence of bytes.

Return Value

The actual number of bytes written into bytes.

Exception typeCondition


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


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


charIndex or charCount or byteIndex is less than zero.


charIndex and charCount do not denote a valid range in chars.


byteIndex is not a valid index in bytes.


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


bytes does not have enough capacity from byteIndex to the end of the array to accommodate the resulting bytes.

To calculate the exact array size required by GetBytes to store the resulting bytes, use GetByteCount. To calculate the maximum array size, use GetMaxByteCount. The GetByteCount method generally allows you to allocate less memory, whereas the GetMaxByteCount method generally executes faster.

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

If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively.

Caution noteCaution

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

The following code example demonstrates how to encode a range of elements from a Unicode character array and store the encoded bytes in a range of elements in a byte array.

using System;
using System.Text;

class UnicodeEncodingExample {
    public static void Main() {
        Byte[] bytes;
        // Unicode characters.
        Char[] chars = new Char[] {
            '\u0023', // #
            '\u0025', // %
            '\u03a0', // Pi
            '\u03a3'  // Sigma
        UnicodeEncoding Unicode = new UnicodeEncoding();
        int byteCount = Unicode.GetByteCount(chars, 1, 2);
        bytes = new Byte[byteCount];
        int bytesEncodedCount = Unicode.GetBytes(chars, 1, 2, bytes, 0);
            "{0} bytes used to encode characters.", bytesEncodedCount

        Console.Write("Encoded bytes: ");
        foreach (Byte b in bytes) {
            Console.Write("[{0}]", b);

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

class UnicodeEncodingExample
    public static void main(String[] args)
        ubyte bytes[];

        // Unicode characters.
        char chars[] = new char[] 
            '\u0023', // #
            '\u0025', // %
            '\u03a0', // Pi
            '\u03a3'  // Sigma
        UnicodeEncoding unicode = new UnicodeEncoding();
        int byteCount = unicode.GetByteCount(chars, 1, 2);
        bytes = new ubyte[byteCount];
        int bytesEncodedCount = unicode.GetBytes(chars, 1, 2, bytes, 0);
        Console.WriteLine("{0} bytes used to encode characters.", 
        Console.Write("Encoded bytes: ");
        for(int iCtr = 0; iCtr < bytes.length; iCtr++) {
            ubyte b = bytes[iCtr];
            Console.Write("[{0}]", String.valueOf(b));
    } //main
} //UnicodeEncodingExample

Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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