当DataTemplate是Button时，ListBox项返回string
我正在创build一个WP 8.1 Silverlight应用程序。
我有一个string名称的ObservableCollection ，它被设置为ListBox的ItemsSource 。 ListBox中button的名称。 然后我想从ListBox提取button，但返回值是stringtypes。
xaml代码是：
<ListBox x:Name="Game_ScrollViewer_online" Margin="41,104,128,6" SelectedValuePath="Current_game_button"> <ListBox.ItemTemplate> <DataTemplate> <Button x:Name="Current_game_button" Content="{Binding}" HorizontalAlignment="Center" Height="80" Margin="-14,6,-15,0" VerticalAlignment="Top" Width="210" Template="{StaticResource Button_CurrentLayout1}" RenderTransformOrigin="0.5,0.5" Foreground="#FFCBECCB" FontFamily="Times New Roman" Click="LoadGame_online" FontSize="16"> </Button> </DataTemplate> </ListBox.ItemTemplate> </ListBox>
然后我想提取button元素：
for (int i = 0; i < Game_ScrollViewer_online.Items.Count; i++) { var tempType = Game_ScrollViewer_online.Items[i].GetType(); Button tempBut = (Game_ScrollViewer_online.Items[i] as Button); //Do stuff with button }
但是，如所说的返回types是string。
为什么不是button？ 有没有办法访问button？
您需要FrameworkTemplate.FindName Method (String, FrameworkElement)为此目的：
private childItem FindVisualChild<childItem>(DependencyObject obj) where childItem : DependencyObject { for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++) { DependencyObject child = VisualTreeHelper.GetChild(obj, i); if (child != null && child is childItem) return (childItem)child; else { childItem childOfChild = FindVisualChild<childItem>(child); if (childOfChild != null) return childOfChild; } } return null; }
然后：
for (int i = 0; i < Game_ScrollViewer_online.Items.Count; i++) { ListBoxItem GameListBoxItem = (ListBoxItem)(Game_ScrollViewer_online.ItemContainerGenerator.ContainerFromIndex(i)); ContentPresenter contentPresenter = FindVisualChild<ContentPresenter>(GameListBoxItem); DataTemplate myDataTemplate = contentPresenter.ContentTemplate; Button tempBut = (Button) myDataTemplate.FindName("Current_game_button", contentPresenter); //Do stuff with button }
为了解决缺less的FindName使用FindDescendant ：
public T FindDescendant<T>(DependencyObject obj) where T : DependencyObject { if (obj is T) return obj as T; int childrenCount = VisualTreeHelper.GetChildrenCount(obj); if (childrenCount < 1) return null; for (int i = 0; i < childrenCount; i++) { DependencyObject child = VisualTreeHelper.GetChild(obj, i); if (child is T) return child as T; } for (int i = 0; i < childrenCount; i++) { DependencyObject child = FindDescendant<T>(VisualTreeHelper.GetChild(obj, i)); if (child != null && child is T) return child as T; } return null; }
