SynchronizingObject Property

Timer.SynchronizingObject Property


Gets or sets the object used to marshal event-handler calls that are issued when an interval has elapsed.

Namespace:   System.Timers
Assembly:  System (in System.dll)

Public Property SynchronizingObject As ISynchronizeInvoke

Property Value

Type: System.ComponentModel.ISynchronizeInvoke

The ISynchronizeInvoke representing the object used to marshal the event-handler calls that are issued when an interval has elapsed. The default is null.

When SynchronizingObject is null, the method that handles the Elapsed event is called on a thread from the system-thread pool. For more information on system-thread pools, see ThreadPool.

When the Elapsed event is handled by a visual Windows Forms component, such as a button, accessing the component through the system-thread pool might result in an exception or just might not work. Avoid this effect by setting SynchronizingObject to a Windows Forms component, which causes the method that handles the Elapsed event to be called on the same thread that the component was created on.


Even if the SynchronizingObject property is not null, Elapsed events can occur after the Dispose or Stop method has been called or after the Enabled property has been set to false, because the signal to raise the Elapsed event is always queued for execution on a thread pool thread. One way to resolve this race condition is to set a flag that tells the event handler for the Elapsed event to ignore subsequent events.

If the Timer is used inside Visual Studio in a Windows Forms designer, SynchronizingObject is automatically set to the control that contains the Timer. For example, if you place a Timer on a designer for Form1 (which inherits from Form), the SynchronizingObject property of Timer is set to the instance of Form1.

.NET Framework
Available since 1.1
Return to top
© 2015 Microsoft