LongListSelector ItemTemplate 내에서 데이터바운드 ContextMenu 참조 - Windows Phone

Question

저는 Windows Phone 7.5용 Silverlight 앱을 작성 중입니다.

설정하고 싶기 때문에 LongListSelector 내부의 ContextMenu를 참조하고 싶습니다. .IsOpen 에게 false ContextMenu가 표시되자마자 Click 이벤트가 호출됩니다.내 생각에는 이것이 자동으로 발생해야 하지만 그렇지 않습니다.

내 MenuItem 중 하나가 <Grid> ~에서 collapsed 에게 visible 이는 PopUp을 모방합니다.코드는 잘 실행되지만 가시성은 실제로 변경됩니다.ContextMenu가 닫히지 않으면 앱의 UI에 그리드가 표시되지 않습니다.

내 XAML은 LongListSelector 이는 ContextMenu ~라고 불리는 Menu ContextMenuItem Click 이벤트에서 참조하고 싶은 항목입니다.

 <toolkit:LongListSelector x:Name="moviesLongList" Background="Transparent" IsFlatList="False" GroupHeaderTemplate="{StaticResource GroupHeaderTemplate}" GroupItemTemplate="{StaticResource GroupItemTemplate}" SelectionChanged="moviesLongList_SelectionChanged" GroupViewClosing="moviesLongList_GroupViewClosing" GroupViewOpened="moviesLongList_GroupViewOpened">

                    <toolkit:LongListSelector.GroupItemsPanel>
                        <ItemsPanelTemplate>
                            <toolkit:WrapPanel/>
                        </ItemsPanelTemplate>
                    </toolkit:LongListSelector.GroupItemsPanel>

                    <toolkit:LongListSelector.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Height="91" Margin="20,0,0,20" Orientation="Horizontal">
                                <toolkit:ContextMenuService.ContextMenu >
                                    <toolkit:ContextMenu x:Name="Menu" Opened="ContextMenu_Opened" Loaded="Menu_Loaded" Unloaded="Menu_Unloaded">
                                        <toolkit:ContextMenu.ItemTemplate>
                                            <DataTemplate>
                                                 <toolkit:MenuItem Header="{Binding}" Click="ContextMenuButton_Click" LostFocus="MenuItem_LostFocus" />
                                            </DataTemplate>
                                        </toolkit:ContextMenu.ItemTemplate>
                                    </toolkit:ContextMenu>
                                </toolkit:ContextMenuService.ContextMenu>

                                <Border HorizontalAlignment="Left" Width="61" Height="91" Background="{Binding ID, Converter={StaticResource ThumbImageConvert}}" />
                                <StackPanel Orientation="Vertical" HorizontalAlignment="Left" Width="395">
                                    <TextBlock x:Name="titleTextBox" Text="{Binding Title, Converter={StaticResource TitleConvert}}" Margin="6,0,6,0" d:LayoutOverrides="Width" FontSize="{StaticResource PhoneFontSizeLarge}" VerticalAlignment="Top" HorizontalAlignment="Left"/>
                                    <TextBlock x:Name="yearTextBox" Text="{Binding Year}" Margin="12,0,0,0" HorizontalAlignment="Left" FontSize="{StaticResource PhoneFontSizeMedium}" Foreground="{StaticResource PhoneSubtleBrush}" />
                                </StackPanel>
                            </StackPanel>
                        </DataTemplate>
                    </toolkit:LongListSelector.ItemTemplate>

                </toolkit:LongListSelector>

ContextMenuItem Click 이벤트 뒤에 있는 내 코드

  private void ContextMenuButton_Click(object sender, RoutedEventArgs e)
  {
        //
        // This is where I want to set Menu.IsOpen = false to close the ContextMenu.
        //

        if ((sender as MenuItem).Header.ToString() == "lend movie")
        {
                DisableAppBarIcons();
                LendPopUpOverlay.Visibility = System.Windows.Visibility.Visible;

        }

        if ((sender as MenuItem).Header.ToString() == "return to collection")
        {
            ... Do stuff
        }

        if ((sender as MenuItem).Header.ToString() == "add to boxset")
        {
             ... Do stuff

        }

        if ((sender as MenuItem).Header.ToString() == "delete")
        {
            ... Do stuff
        }

   }

ContextMenu의 ItemSource를 ContextMenu_Opened 이벤트.필드는 둘 다 유형입니다. List<String>.

private void ContextMenu_Opened(object sender, RoutedEventArgs e)
    {
        LentMovieObj = (sender as ContextMenu).DataContext as Movies;

        if (LentMovieObj.IsLent)
        {
            (sender as ContextMenu).ItemsSource = menuItemsReturn;
        }
        else
        {
            (sender as ContextMenu).ItemsSource = menuItemsLendOut;
        }
    }

Answer 1

ContextMenu가 왜 닫히지 않는지 잘 모르겠지만 여기에 두 가지 해결 방법이 있습니다.첫 번째는 MenuItem의 부모를 가져오는 것입니다.

private T GetParentOfType<T>(DependencyObject obj) where T : class
{
    if (obj == null) return null;

    var parent = VisualTreeHelper.GetParent(obj);
    while (parent != null)
    {
        if (parent is T) return parent as T;

        parent = VisualTreeHelper.GetParent(parent);
    }

    return null;
}

그런 다음 클릭 핸들러에서 메뉴를 가져옵니다.

var menu = GetParentOfType<ContextMenu>(sender as MenuItem);
menu.IsOpen = false;

두 번째 해결책은 IsOpen을 지원 뷰 모델에 바인딩하는 것입니다.

<toolkit:ContextMenuService.ContextMenu >
    <toolkit:ContextMenu x:Name="Menu" Opened="ContextMenu_Opened" Loaded="Menu_Loaded" Unloaded="Menu_Unloaded" IsOpen="{Binding IsOpen}" ItemsSource="{Binding Items}">
        <toolkit:ContextMenu.ItemTemplate>
            <DataTemplate>
                <toolkit:MenuItem Header="{Binding}" Click="ContextMenuButton_Click" LostFocus="MenuItem_LostFocus" />
             </DataTemplate>
        </toolkit:ContextMenu.ItemTemplate>
     </toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>

공개 이벤트를 변경하세요.

private void ContextMenu_Opened(object sender, RoutedEventArgs e)
{
    LentMovieObj = (sender as ContextMenu).DataContext as Movies;

    if (LentMovieObj.IsLent)
    {
        (sender as ContextMenu).DataContext = new ContextMenuViewModel(menuItemsReturn);
    }
    else
    {
        (sender as ContextMenu).DataContext = ContextMenuViewModel(menuItemsLendOut);
    }
}

그런 다음 뷰 모델

public class ContextMenuViewModel : INotifyPropertyChanged
{
    private bool _isOpen = true;

    public ContextMenuViewModel(IEnumerable<string> items)
    {
        Items = items;
    }

    public event PropertyChangedEventHandler PropertyChanged;

    public bool IsOpen
    {
        get { return _isOpen; }
        set { _isOpen = value; OnPropertyChanged("IsOpen"); }
    }

    public IEnumerable<String> Items { get; set; }

    protected virtual void OnPropertyChanged(string propertyName)
    {
        var handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

그런 다음 ViewModel의 IsOpen 속성을 false로 설정합니다.