Make a form not focusable in C#

Question

I\'m wanting to write a virtual keyboard, like windows onscreen keyboard for touchscreen pcs. But I\'m having problem with my virtual keyboard stealing the focus from the ap

Answer 1

Instead of trying to reset the active window after your one has been clicked, I would rather try to prevent your window from receiving focus/being activated.

Have a look at this article. At the end, the author briefly explains how this can be done:

How can I prevent my window from getting activation and focus when shown?

In Windows Forms 2.0 there is a new property called ShowWithoutActivation – which you would need to override on the Form. In native applications you can use SetWindowPos with the SWP_NOACTIVATE flag or the ShowWindow with the SW_SHOWNA flag.

Furthermore, in this article he provides a code example for Windows Forms:

If you want a full-on form, you can now override a property called ShowWithoutActivation:

public class NoActivateForm : Form 
{
    protected override bool ShowWithoutActivation => true;  
}

Keep in mind this does not “prevent” activation all the time – you can still activate by calling the Activate(), Focus()… etc methods. If you want to prevent clicks on the client area from activating the window, you can handle the WM_MOUSEACTIVATE message.

private const int WM_MOUSEACTIVATE = 0x0021, MA_NOACTIVATE = 0x0003;

protected override void WndProc(ref Message m)
{
    if (m.Msg == WM_MOUSEACTIVATE) 
    {
         m.Result = (IntPtr)MA_NOACTIVATE;
         return;
    }
    base.WndProc(ref m);
}