How can I prevent other apps from stealing the focus?

Question

I have a fullscreen window with the Topmost property set to true. Whenever an application changes its WindowState property, my window is automatically minimized even though it has the active focus. For example, the code below exemplifies the problem. 3 seconds after the window is deactivated, it changes from Minimized to Normal, minimizing the other fullscreen application.

// Topmost = false
private void Form1_Deactivate(object sender, EventArgs e)
{
    System.Threading.Thread.Sleep(3000);
    this.WindowState = FormWindowState.Normal;
}

Is there a way to preserve the fullscreen window's WindowState property in such a case? I want the user to choose to minimize the fullscreen app, so I want to stop other programs from stealing the focus.

Answer 1

You may want to investigate "Kiosk Mode".

Answer 2

If this is a kiosk application and you are the only program running on the computer then fine. Otherwise this is a really bad idea and that's why there is not a documented way of doing it. As Raymund Chen says this kind of question should be followed with the thought experiment "what if two programs did this?":

http://blogs.msdn.com/oldnewthing/archive/2005/06/07/426294.aspx

Answer 3

Perhaps this is what you want: Windows Form in Full Screen "Kiosk Mode".

Otherwise I'll second Henk's recomendation.