Thank you! I wound up with a slightly different solution, but you definitely pointed me in the right direction with your answer.
For my application, I have a lot of controls in main, and most of the method calls on main were occurring from within the scope of main, so it was simpler to use the default { get; set } within MainWindow.xaml.cs (or to just define the controls in XAML).
In my parent window's code-behind, I launch the MainWindow in a separate thread like this (simplified example). The key is to define main globally, even though it is instantiated inside of Window_Loaded():
public ParentWindow()
{
InitializeComponent();
}
MainWindow main;
private void Window_Loaded(object sender, RoutedEventArgs e)
{
Thread otherThread = new Thread(() =>
{
main = new MainWindow();
main.Show();
main.Closed += (sender2, e2) =>
main.Dispatcher.InvokeShutdown();
System.Windows.Threading.Dispatcher.Run();
});
otherThread.SetApartmentState(ApartmentState.STA);
otherThread.Start();
}
Then in my MainWindow code-behind, I just interact with the controls as though it is a simple single-threaded application (there is no control of the parent thread from the child thread in my case). I can, however, control main from the parent thread like this:
private void button_Click(object sender, RoutedEventArgs e)
{
main.Dispatcher.Invoke(new Action(delegate ()
{
main.myControl.myMethod();
}));
}
By doing it this way, I avoid the complexity of defining everything in code-behind and using the dispatcher from within the code-behind of MainWindow.xaml.cs. There are only a few spots in my application where I modify main from the parent window, so this was simpler for me, but your approach seems equally valid. Thanks again!