how can i tell a wpf window overlays another one

Question

in wpf ,how can i tell a wpf window overlays anther one? Image there are two windows, they are both not active, one should overlay the other one, how can i tell that in my app

Answer 1

Do you mean that the window that you open with ShowDialog should overlap the window that created it?

Window1 window1 = new Window1();
window1.Top = this.Top;
window1.Left = this.Left;
window1.Width = this.Width;
window1.Height = this.Height;
window1.ShowDialog();