当DataTemplate为Button时，ListBox项目返回字符串

Question

我正在创建WP 8.1 Silverlight应用程序。我有一个ObservableCollection字符串名称，它被设置到的ItemsSource的ListBox。中的按钮名称是哪些ListBox。然后，我想从中提取按钮ListBox，但是返回值为type string。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}但是正如所说的，返回类型是字符串。为什么不是按钮？有没有办法访问按钮？

Answer 1

FrameworkTemplate.FindName Method (String, FrameworkElement)为此，您需要：

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

}

要解决这样的缺失FindName用法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;

}