C# dispatcher // access mainwindow from another class

windowstuff.cs

       MainWindow.main.Dispatcher.Invoke(new Action(delegate ()
                {
                    var that = MainWindow.main.lblZuege;
                    that.Content = zuege;
                }));
                
                
                 public static MainWindow main;
        public MainWindow()
        {
            InitializeComponent();
            main = this;
        }