Encoding::GetBytes Method (Char*, Int32, Byte*, Int32)
When overridden in a derived class, encodes a set of characters starting at the specified character pointer into a sequence of bytes that are stored starting at the specified byte pointer.
Assembly: mscorlib (in mscorlib.dll)
[ComVisibleAttribute(false)] [CLSCompliantAttribute(false)] public: virtual int GetBytes( wchar_t* chars, int charCount, unsigned char* bytes, int byteCount )
- Type: System::Char*
A pointer to the first character to encode.
- Type: System::Int32
The number of characters to encode.
- Type: System::Byte*
A pointer to the location at which to start writing the resulting sequence of bytes.
- Type: System::Int32
The maximum number of bytes to write.
Return ValueType: System::Int32
The actual number of bytes written at the location indicated by the bytes parameter.
chars is nullptr.
bytes is nullptr.
charCount or byteCount is less than zero.
byteCount is less than the resulting number of bytes.
A fallback occurred (see Character Encoding in the .NET Framework for complete explanation)
To calculate the exact array size that GetBytes requires to store the resulting bytes, the application should use 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.
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 object provided by the GetDecoder 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 GetBytes method expects discrete conversions, in contrast to the Encoder::GetBytes method, which handles multiple conversions on a single input stream.
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 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.
Requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.
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.