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

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

Namespace:  System.Text
Assemblies:   mscorlib (in mscorlib.dll)
  System.Text.Encoding.Extensions (in System.Text.Encoding.Extensions.dll)

public override int GetBytes(
	string chars,
	int charIndex,
	int charCount,
	byte[] bytes,
	int byteIndex
)

Parameters

chars
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

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.

Data to be converted, such as data read from a stream, can 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.

ASCIIEncoding does not provide error detection. Any Unicode character greater than U+007F is encoded as the ASCII question mark ("?").

Caution noteCaution

For security reasons, your application is recommended to use UTF8Encoding, UnicodeEncoding, or UTF32Encoding and enable error detection.

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

        ASCIIEncoding ascii = new ASCIIEncoding();

        int byteCount = ascii.GetByteCount(chars, 1, 2);
        bytes = new Byte[byteCount];
        int bytesEncodedCount = ascii.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: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0
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