UTF8Encoding.GetBytes Method (Char*, Int32, Byte*, Int32)


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.

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

public override unsafe int GetBytes(
	char* chars,
	int charCount,
	byte* 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 Value

Type: System.Int32

The actual number of bytes written at the location indicated by bytes.

Exception Condition

chars is null.


bytes is null.


charCount or byteCount is less than zero.


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


byteCount is less than the resulting number of bytes.


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


EncoderFallback is set to EncoderExceptionFallback.

To calculate the exact array size required by GetBytes to store the resulting bytes, you call the GetByteCount method. To calculate the maximum array size, you call the GetMaxByteCount method. The GetByteCount method generally allocates less memory, while the GetMaxByteCount method generally executes faster.

With error detection, an invalid sequence causes this method to throw an ArgumentException exception. 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, use the Decoder or the Encoder returned by the GetDecoder method or the GetEncoder method, respectively.

To ensure that the encoded bytes are decoded properly when they are saved as a file or as a stream, you can prefix a stream of encoded bytes with a preamble. Inserting the preamble at the beginning of a byte stream (such as at the beginning of a series of bytes to be written to a file) is the developer's responsibility. The GetBytes method does not prepend a preamble to the beginning of a sequence of encoded bytes.


Requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

Universal Windows Platform
Available since 10
.NET Framework
Available since 2.0
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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