Solution for InvalidOperationException: "Cross-thread operation not valid: Control '<name>' accessed from a thread other than the thread it was created on."

part1.cs

private void delegate MyDelegate(); // This is the delegate that will be invoked from the main thread if needed

part2.cs

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        MyDelegate myDelegate = new MyDelegate(myMethod); // add "myMethod()" to the delegate
    }
}

part3.cs

private void myMethod()
{
    if (<formControl>.InvokeRequired) // This is hit if a background thread calls the surrounding method
    {
	    this.BeginInvoke(myDelegate); // Method definition: BeginInvoke(Delegate method, params object[] args)
	    // If called from the WPF window's code (usually "MainWindow.cs"), it will cause the GUI thread to invoke the code, allowing it to update the GUI on the GUI thread!
	    // this.BeginInvoke() and this.Invoke() are both methods that invoke a delegate from the GUI thread, as long as "this" is the WPF main window or Form element.
	}
	else
	{
		// update the form control directly
		<formElement>.Text = "Updated from the GUI thread.";
	}
}