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SerialPort.IsOpen Property

Gets a value indicating the open or closed status of the SerialPort object.

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

public bool IsOpen { get; }
/** @property */
public boolean get_IsOpen ()

public function get IsOpen () : boolean

Not applicable.

Property Value

true if the serial port is open; otherwise, false. The default is false.

Exception typeCondition


The IsOpen value passed is a null reference (Nothing in Visual Basic).


The IsOpen value passed is an empty string ("").

The IsOpen property tracks whether the port is open for use by the caller, not whether the port is open by any application on the machine.

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

.NET Compact Framework

Supported in: 2.0