WriteByte Method

Stream.WriteByte Method

Writes a byte to the current position in the stream and advances the position within the stream by one byte.

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

public virtual void WriteByte(
	byte value


Type: System.Byte
The byte to write to the stream.


An I/O error occurs.


The stream does not support writing, or the stream is already closed.


Methods were called after the stream was closed.

Use the CanWrite property to determine whether the current instance supports writing.

Notes to Implementers

The default implementation on Stream creates a new single-byte array and then calls Write. While this is formally correct, it is inefficient. Any stream with an internal buffer should override this method and provide a much more efficient version that writes to the buffer directly, avoiding the extra array allocation on every call.

.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

© 2015 Microsoft