private void navigationListView_SelectionChanged(object sender, SelectionChangedEventArgs e) { if (navigationListView.SelectedIndex == 0) { ListUserControl listUserControl = new ListUserControl(); mainGrid.Children.Clear(); mainGrid.Children.Add(listUserControl); listUserControl.commandExecutionHandler += commandExecution; } if (navigationListView.SelectedIndex == 2) { AddingUserControl addingUserControl = new AddingUserControl(0, -1); mainGrid.Children.Clear(); mainGrid.Children.Add(addingUserControl); addingUserControl.commandExecutionHandler += commandExecution; } }