Riferimento di un contesto del databoundMenu all'interno di un LongListellector ItemTemplate: Windows Plase

Question

Sto scrivendo un argenteo per l'app Windows Phone 7.5.

Voglio fare riferimento al contextmenu all'interno del mio longlistElector perché voglio impostare .IsOpen in false non appena viene chiamato l'evento del contextMenu Click. Il mio pensiero era che questo dovrebbe accadere automaticamente ma non lo fa.

Uno dei miei MenuTem consente la visibilità di un <Grid> da collapsed a visible che mimica un popup. Mentre il codice esegue bene e la visibilità cambia davvero. L'UI dell'app non mostra la griglia a meno che il contextmenu si chiuda.

Il mio XAML del LongListSelector che contiene un ContextMenu chiamato Menu che desidero fare riferimento nell'evento ContextMenItem Click.

 <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>

.

Il mio codice dietro contextMenIuItem Click Event

  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
        }

   }

.

Ho impostato gli elementi del contextMenu nell'evento ContextMenu_Opened. I campi sono entrambi di tipo 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

Non è sicuro del motivo per cui il contextMenu non si chiude, ma qui ci sono due soluzioni.Il primo è quello di ottenere il genitore del Menuitem.

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;
}

.

Quindi ottieni il menu dal tuo click handler

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

.

La seconda soluzione è per legare gli isopene a un campanello di supporto

<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>

.

Cambia il tuo evento aperto:

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);
    }
}

.

Allora un ViewModel

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));
        }
    }
}

.

Quindi imposta la proprietà ISOPEN del tuo ViewModel su FALSE;