Export (0) Print
Expand All

UTF8Encoding.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
)

Parameters

s
Type: System.String

The String containing the set of characters to encode.

charIndex
Type: System.Int32

The index of the first character to encode.

charCount
Type: System.Int32

The number of characters to encode.

bytes
Type: System.Byte[]

The byte array to contain the resulting sequence of bytes.

byteIndex
Type: System.Int32

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

Return Value

Type: System.Int32
The actual number of bytes written into bytes.

ExceptionCondition
ArgumentNullException

s is null.

-or-

bytes is null.

ArgumentOutOfRangeException

charIndex or charCount or byteIndex is less than zero.

-or-

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

-or-

byteIndex is not a valid index in bytes.

ArgumentException

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

-or-

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

EncoderFallbackException

A fallback occurred (see Character Encoding in the .NET Framework for complete 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.

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 uses the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively.

NoteNote

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

The following example demonstrates how to use the GetBytes method 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 UTF8EncodingExample {
    public static void Main() {
        Byte[] bytes;
        // Unicode characters.
        Char[] chars = new Char[] {
            '\u0023', // #
            '\u0025', // %
            '\u03a0', // Pi
            '\u03a3'  // Sigma
        };

        UTF8Encoding utf8 = new UTF8Encoding();

        int byteCount = utf8.GetByteCount(chars, 1, 2);
        bytes = new Byte[byteCount];
        int bytesEncodedCount = utf8.GetBytes(chars, 1, 2, bytes, 0);

        Console.WriteLine(
            "{0} bytes used to encode characters.", bytesEncodedCount
        );

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

.NET Framework

Supported in: 4.5.2, 4.5.1, 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 8, Silverlight 8.1

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.

Show:
© 2014 Microsoft