Export (0) Print
Expand All

Encoding.GetBytes Method (Char[], Int32, Int32)

When overridden in a derived class, encodes a set of characters from the specified character array into a sequence of bytes.

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

abstract GetBytes : 
        chars:char[] * 
        index:int * 
        count:int -> byte[] 
override GetBytes : 
        chars:char[] * 
        index:int * 
        count:int -> byte[] 

Parameters

chars
Type: System.Char[]
The character array containing the set of characters to encode.
index
Type: System.Int32
The index of the first character to encode.
count
Type: System.Int32
The number of characters to encode.

Return Value

Type: System.Byte[]
A byte array containing the results of encoding the specified set of characters.

ExceptionCondition
ArgumentNullException

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

ArgumentOutOfRangeException

index or count is less than zero.

-or-

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

EncoderFallbackException

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

-and-

EncoderFallback is set to EncoderExceptionFallback.

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, the application should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.

The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding. The Encoding.GetBytes method expects discrete conversions, in contrast to the Encoder.GetBytes method, which handles multiple conversions on a single input stream.

Several versions of GetByteCount and GetBytes are supported. The following are some programming considerations for use of these methods:

  • The application might need to encode many input characters to a code page and process the characters using multiple calls. In this case, your application probably needs to maintain state between calls, taking into account the state that is persisted by the Encoder object being used. (For example, a character sequence that includes surrogate pairs might end with a high surrogate. The Encoder will remember that high surrogate so that it can be combined with a low surrogate at the beginning of a following call. Encoding won't be able to maintain the state, so the character will be sent to the EncoderFallback.)

  • If the application handles string inputs, it is recommended to use the string version of GetBytes.

  • The Unicode character buffer version of GetBytes allows some fast techniques, particularly with multiple calls using the Encoder object or inserting into existing buffers. Bear in mind, however, that this method version is sometimes unsafe, since pointers are required.

  • If your application must convert a large amount of data, it should reuse the output buffer. In this case, the GetBytes version that supports byte arrays is the best choice.

  • Consider using the Encoder.Convert method instead of GetByteCount. The conversion method converts as much data as possible, and does throw an exception if the output buffer is too small. For continuous encoding of a stream, this method is often the best choice.

The following example determines the number of bytes required to encode three characters from a character array, encodes the characters, and displays the resulting bytes.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 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

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

Community Additions

ADD
Show:
© 2014 Microsoft