Thread Print problem

Question

I have an application which opens some Windows in a new Thread. I have a custom build Menu with a print command.
The problem I'm facing is that when I want to print from the threaded Window I get a System.Invalidoperationexception:
"The calling thread cannot access this object because a different thread owns it"
I think the issue is that the visual is in the threaded window, but the Printdialog gets executed on main thread, as I understand this ???
Sample App for testing and review at:
Sample
public static void StartPrint(Window win, string name)
            FrameworkElement vs = (FrameworkElement)ControlUtility.FindVisualChildByName<Grid>(win, "MainGrid");
//Getting the error here
            Application.Current.Dispatcher.Invoke(new Action(() =>
                    PrintDialog pd = new PrintDialog();
                    if (pd.ShowDialog() == true)
                        pd.PrintVisual(vs, name);

Answer 1

Yes.
That's your problem.
This bit
Application.Current.Dispatcher.Invoke(new Action(() =>
Is on one UI thread.
Your window is created on another ui thread and this isn't going to work.
You could possibly find that other thread but this isn't really a good plan.
I have a piece of advice for you.
DO NOT OPEN WINDOWS ON DIFFERENT THREADS !!!!!!!
It's a bad idea.
No matter what benefits you think this will deliver, it is a disaster waiting to happen for you.
I led a team on a project where we did this.
Had to back it out in the end.
The solution to your issue is to open all windows on the same UI thread.
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