private void LiveAction(object param) { View.MainWindow mainwindow = (View.MainWindow)Application.Current.MainWindow; ViewModel.MainWindow mainwindowVM = (ViewModel.MainWindow)mainwindow.DataContext; mainwindowVM.ViewStack.Add((UserControl)mainwindow.contentcontrol.Content); View.LiveChartsWindow view = new View.LiveChartsWindow(); ViewModel.LiveChartsViewModel vm = new LiveChartsViewModel(); view.DataContext = vm; mainwindow.contentcontrol.Content = view; }