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Process.SynchronizingObject Property

Updated: September 2008

Gets or sets the object used to marshal the event handler calls that are issued as a result of a process exit event.

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

public ISynchronizeInvoke SynchronizingObject { get; set; }

Property Value

Type: System.ComponentModel.ISynchronizeInvoke
The ISynchronizeInvoke used to marshal event handler calls that are issued as a result of an Exited event on the process.

When SynchronizingObject is null, methods handling the Exited event are called on a thread from the system thread pool. For more information on system thread pools, see ThreadPool.

When the Exited event is handled by a visual Windows Forms component, such as a Button, accessing the component through the system thread pool might not work, or might result in an exception. Avoid this by setting SynchronizingObject to a Windows Forms component, which causes the methods handling the Exited event to be called on the same thread on which the component was created.

If the Process is used inside Visual Studio 2005 in a Windows Forms designer, SynchronizingObject is automatically set to the control containing the Process. For example, if you place a Process on a designer for Form1 (which inherits from Form) the SynchronizingObject property of Process is set to the instance of Form1, as shown in the following example. 

    this.process1.StartInfo.Domain = "";
    this.process1.StartInfo.LoadUserProfile = false;
    this.process1.StartInfo.Password = null;
    this.process1.StartInfo.StandardErrorEncoding = null;
    this.process1.StartInfo.StandardOutputEncoding = null;
    this.process1.StartInfo.UserName = "";
    this.process1.SynchronizingObject = this;

Typically, this property is set when the component is placed inside a control or form, because those components are bound to a specific thread.

   private MyButton button1;
   private void button1_Click(object sender, System.EventArgs e)
      Process myProcess = new Process();
      ProcessStartInfo myProcessStartInfo= new ProcessStartInfo("mspaint");
      myProcess.StartInfo = myProcessStartInfo;
      myProcess.Exited += new EventHandler(MyProcessExited);
      // Set 'EnableRaisingEvents' to true, to raise 'Exited' event when process is terminated.
      myProcess.EnableRaisingEvents = true;
      // Set method handling the exited event to be called  ; 
      // on the same thread on which MyButton was created.
      myProcess.SynchronizingObject = button1;
      MessageBox.Show("Waiting for the process 'mspaint' to exit....");
   private void MyProcessExited(Object source, EventArgs e)
      MessageBox.Show("The process has exited.");

public class MyButton:Button


  • LinkDemand 

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

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0




September 2008

Added an example that shows how to set the SynchronizingObject property.

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