DirectCast任何窗口，不仅是主窗口？

Question

I've been trying to edit variables in other windows like in VB.NET using DirectCast. This seems to be working very well with the main window, as I use

Private Main As MainWindow = DirectCast(Application.Current.MainWindow, MainWindow)

But, I am unable to find a way to use this with a window other than the main one. For now, I am stuck using this

Dim WindowOne As New Window1
WindowOne.Show()

This works, but I would rather not have to create a new instance of the window each time I want it to open. I have tried using

Private WindowOne As Window1 = DirectCast(Application.Current.Windows.OfType(Of Window1).First(), Window1)

but it always gives me an error saying that "The sequence contains no elements".

Is there any other way to do this? What am I doing wrong?

Answer 1

The correct syntax is below.

Private WindowOne As Window1 = Application.Current.Windows.OfType(Of Window1)().FirstOrDefault()
If Not WindowOne Is Nothing Then
  'object is available here
End If