This documentation is archived and is not being maintained.

SerialPort.BytesToWrite Property

Note: This property is new in the .NET Framework version 2.0.

Gets the number of bytes of data in the send buffer.

Namespace: System.IO.Ports
Assembly: System (in system.dll)

public int BytesToWrite { get; }
/** @property */
public int get_BytesToWrite ()

public function get BytesToWrite () : int

Property Value

The number of bytes of data in the send buffer.

Exception typeCondition


The port is in an invalid state.


The stream is closed. This can occur because the Open method has not been called or the Close method has been called.

The send buffer includes the serial driver's send buffer as well as internal buffering in the SerialPort object itself.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0

.NET Compact Framework

Supported in: 2.0