Question

The following code does not exit the application. How can I exit the application and make sure all the running threads are closed?

foreach (Form form in Application.OpenForms)
{
    form.Close();
}
Application.Exit();

Answer 1

You don’t show the use of any threads in your code, but let’s suppose you do have threads in it. To close all your threads you should set all of them to background threads before you start them, then they will be closed automatically when the application exits, e.g.:

Thread myThread = new Thread(...);
myThread.IsBackground = true; // <-- Set your thread to background
myThread.Start(...);

A “HOWTO: Stop Multiple Threads” article from microsoft: http://msdn.microsoft.com/en-us/library/aa457093.aspx