Executes code from a wpf app on an STA thread synchronously and sets the cursor to busy.

ExecuteOnSTAThread.cs

void ExecuteOnSTAThread(ThreadStart t)
{
    Mouse.OverrideCursor = Cursors.Wait; // Make the mouse cursor a busy spinner 
    Thread thread = new Thread(t);
    thread.SetApartmentState(ApartmentState.STA);
    thread.Start();
    thread.Join();
    Mouse.OverrideCursor = null; 
}

ExecuteOnSTAThread(new ThreadStart(() =>
{
    try
    {
        // TODO: Your code goes here.
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
    }
}));