c# - Detect if Main UI is closing

Question

I'm currently developing a class library. I'm having trouble finding a way to detect if the Main UI is closing.

Is there a way to know that from the class library project?

My purpose of this is to cancel all the threads that is currently running if the Main UI is closing.

Answer 1

You could use ApplicationExit event in Program.cs file, provided you have list of all the running threads, you could close.

Application.ApplicationExit += new EventHandler(Application_ApplicationExit);


static void Application_ApplicationExit(object sender, EventArgs e)
    {
        //do something
    }

Other option is to track FormClosing event for the main Form.