How to make a WPF window be on top of all other windows of my app (not system wide)?

Question

I want my window to be on top of all other windows in my application only. If I set the TopMost property of a window, it becomes on top of all windows of al

Answer 1

In the popup window, overloads the method Show() with a parameter:

Public Overloads Sub Show(Caller As Window)
    Me.Owner = Caller
    MyBase.Show()
End Sub

Then in the Main window, call your overloaded method Show():

Dim Popup As PopupWindow

Popup = New PopupWindow
Popup.Show(Me)