UIElementSilverlight for WP7 アプリケーションの座標から検索しようとしています。
ここに私の XAML があります:
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid.RowDefinitions>
    <RowDefinition Height="Auto"/>
    <RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
    <TextBlock x:Name="ApplicationTitle" Text="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>
    <TextBlock x:Name="PageTitle" Text="page name" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
</StackPanel>
<Canvas x:Name="ContentPanel" Grid.Row="1">
    <Rectangle Canvas.Top="20" Canvas.Left="20" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="90" Canvas.Left="20" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="160" Canvas.Left="20" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="20" Canvas.Left="90" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="90" Canvas.Left="90" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="160" Canvas.Left="90" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="20" Canvas.Left="160" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="90" Canvas.Left="160" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="160" Canvas.Left="160" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="20" Canvas.Left="230" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="90" Canvas.Left="230" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
    <Rectangle Canvas.Top="160" Canvas.Left="230" Width="50" Height="50" Fill="Aqua" Tap="Rectangle_Tap" />
</Canvas>
と私の分離コード:
public partial class MainPage : PhoneApplicationPage
{
    public MainPage()
    {
        InitializeComponent();
    }
    private void Rectangle_Tap(object sender, GestureEventArgs e)
    {
        Rectangle r = (Rectangle)sender;
        double x = (double)r.GetValue(Canvas.LeftProperty);
        double y = (double)r.GetValue(Canvas.TopProperty);
        Debug.WriteLine(x + "," + y);
        var query = VisualTreeHelper.FindElementsInHostCoordinates(new Point(x - 70, y), ContentPanel).Union(
            VisualTreeHelper.FindElementsInHostCoordinates(new Point(x + 70, y), ContentPanel)).Union(
            VisualTreeHelper.FindElementsInHostCoordinates(new Point(x, y - 70), ContentPanel)).Union(
            VisualTreeHelper.FindElementsInHostCoordinates(new Point(x, y + 70), ContentPanel)).Union(
            VisualTreeHelper.FindElementsInHostCoordinates(new Point(x, y), ContentPanel));
        foreach (UIElement element in query.OfType<Rectangle>())
        {
            // never goes here
            ContentPanel.Children.Remove(element);
        }
    }
}
しかし問題は、メソッドが Rectangle を返さないことです。
私のコードの何が問題になっていますか?
助けてくれてありがとう。よろしくお願いします