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

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

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

public override int GetBytes (
	char[] chars,
	int charIndex,
	int charCount,
	byte[] bytes,
	int byteIndex
public int GetBytes (
	char[] chars, 
	int charIndex, 
	int charCount, 
	byte[] bytes, 
	int byteIndex
public override function GetBytes (
	chars : char[], 
	charIndex : int, 
	charCount : int, 
	bytes : byte[], 
	byteIndex : int
) : int
Not applicable.



The character array 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


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


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


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 chars 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.


A fallback occurred (see Understanding Encodings for fuller explanation)


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.

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


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 GetBytes method to encode a range of characters from a String 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;
        String chars = "Unicode Encoding Example";
        UnicodeEncoding Unicode = new UnicodeEncoding();
        int byteCount = Unicode.GetByteCount(chars.ToCharArray(), 8, 8);
        bytes = new Byte[byteCount];
        int bytesEncodedCount = Unicode.GetBytes(chars, 8, 8, bytes, 0);
            "{0} bytes used to encode string.", 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[];
        String chars = "Unicode Encoding Example";
        UnicodeEncoding unicode = new UnicodeEncoding();
        int byteCount = unicode.GetByteCount(chars.ToCharArray(), 8, 8);
        bytes = new ubyte[byteCount];
        int bytesEncodedCount = unicode.GetBytes(chars, 8, 8, bytes, 0);
        Console.WriteLine("{0} bytes used to encode string.", 
        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 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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