WPF Dialog - Allow interaction with underlying windows

Question

Is it possible with WPF to open a dialog (a new window) and keep the possibility to interact with the underlying main window?

I imagine a help window that is placed next to the main window and doesn't block interaction.

How could I easily check where the mouse is over and show a info to the specific area?

Answer 1

you could call .Show() and set the Topmost Property to true.

A window whose Topmost property is set to true appears above all windows whose Topmost properties are set to false.

In the group of windows that have Topmost property is set to true, the window that is currently activated is the topmost window. Likewise for the group of windows that have Topmost property is set to false. See http://msdn.microsoft.com/en-us/library/system.windows.window.topmost.aspx