Getting a NotSupportedException when trying to close my Form

Question

As you can see in this answer https://stackoverflow.com/a/39704027/6886308 ,you can tell when an winform was closed like in the example ,the Notepad. And I tried playing with it a bit and while the code in the example worked ,something bothered me.

What if I want to close my app when the Notepad was closed?So I tried something like:

void watcher_EventArrived(object sender, EventArrivedEventArgs e)
{
    if ((string)e.NewEvent["ProcessName"] == "notepad.exe")
        {
           Close();
        }
}

And it is trowing me an un-handled error ,so I was thinking maybe the focus remained on the winform?Or what is the problem in fact?

EDIT 1:

Here is a screenshot of the exception

What error are you getting exactly? – MarioDS Sep 27 '16 at 07:40 — MarioDS, Sep 27 '16 at 07:40

score 0 · Answer 1 · answered Sep 27 '16 at 07:54

0

Your event handler is on another thread but you're calling Close on your form which isn't allowed - you need to have something like Invoke((Action)Close); which will marshall the call back to the UI thread.

answered Sep 27 '16 at 07:54

auburg

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score 0 · Accepted Answer · answered Sep 27 '16 at 07:55

You are getting the exception because you are trying to close the process from a thread other than on what it was created on. This is not allowed.

do it like this

void watcher_EventArrived(object sender, EventArrivedEventArgs e)
{
    if ((string)e.NewEvent["ProcessName"] == "notepad.exe")
        {
           this.Invoke((MethodInvoker) delegate
            {

               Close();
            });
        }
}

Getting a NotSupportedException when trying to close my Form

EDIT 1:

2 Answers2