Prevent a form from getting focus

Question

I am making an application that uses multiple forms at the same time. I have one form that is a "background" form for all the others. The problem is that when I click it, the form comes to the front. I want to keep it behind my other forms, but still in front of other windows that may be open (other running applications). How do I do this?

Alan · Answer

The code is for the activation of the entire application. For individual forms you can handle the .NET Form.Activated or Form.Deactivate events.

Scott · Answer

That's not quite what I'm looking for but I'll play around with it and see what I can do with it. Is that code for the activation of each individual form or for the entire application?

Alan · Answer

To my knowledge there's no such event in the .NET framework. However you can override WndProc() in the form class you'd like to keep on top (or not) to watch for the WM_ACTIVATEAPP message and then handle it accordingly. Something like this: private const int WM_ACTIVATEAPP = 0x1C; protected override void WndProc(ref Message m) { if (m.Msg == WM_ACTIVATEAPP) { if ( m.WParam.ToInt32() != 0 ) { // application is receiving focus this.Topmost = true; } else { // application is losing focus this.Topmost = false; } } base.WndProc(ref m); }

Scott · Answer

I already tried that but when I click on another application in the taskbar my application is still on top. Is there an event that fires when the application loses focus?

Bechir Bejaoui · Answer

set the property TopMost of the from that you want to be always on top to true yourForm.TopMost = true;