Manipulation events not firing - wpf

Question

I'm new to developing in WPF for touchscreens, and I'm having trouble interpreting manipulation events. What I want to do is fairly simple I believe: when the user pinches anywhere on a UserControl, it will perform an action.
So, in the control I have (this is Surface 2.0 / Windows Touch):
XAML
<Grid Background="White" IsManipulationEnabled="True"
ManipulationStarting="Grid_ManipulationStarting"
ManipulationDelta="Grid_ManipulationDelta">
<!--Some content controls-->
</Grid>
C#
private void Grid_ManipulationStarting(object sender, ManipulationStartingEventArgs e)
{
e.ManipulationContainer = this;
}
private void Grid_ManipulationDelta(object sender, ManipulationDeltaEventArgs e)
{
//do the thing... you know, that thing you do
}
However, neither of these events fire when I rub my hands all over the screen. I think I must not understand the routing of the event in this situation. My monitor (3M MicroTouch PX) has not had any trouble understanding touch events or built-in manipulation like in ScatterViewItems.
EDIT: I removed controls from inside the Grid and they fire now, so I guess manipulations are being intercepted by the content. Sorry, should have been more clear about the contents of the control, because they're the problem it seems.
Specifically I think it has to do with the fact that I have a SurfaceListBox inside. I would imagine the SurfaceListBox is intercepting manipulation. Is there a way I can tell it to step off? I'm still trying to wrap my head around the way WPF does events.
Edit2: Going to paste some more complete code.
SEMANTICPANEL.XAML FULL
<UserControl x:Class="SemanticZoom.SemanticPanel"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:SemanticZoom"
xmlns:views="clr-namespace:SemanticZoom.Views"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
</UserControl.Resources>
<Grid Background="White" IsManipulationEnabled="True" ManipulationStarting="Grid_ManipulationStarting" ManipulationDelta="Grid_ManipulationDelta">
<views:CategoryView x:Name="CategoryView"/>
<views:ShelfView x:Name="ShelfView" Visibility="Hidden" />
<views:BookView x:Name="BookView" Visibility="Hidden" />
</Grid>
SEMANTICPANEL.CS FULL
public partial class SemanticPanel : UserControl
{
public SemanticPanel()
{
InitializeComponent();
CategoryView.CategorySelected += new EventHandler(CategoryView_CategorySelected);
ShelfView.BookSelected += new EventHandler(ShelfView_BookSelected);
ShelfView.ZoomOut += new EventHandler(View_ZoomOut);
}
void View_ZoomOut(object sender, EventArgs e)
{
if (sender == ShelfView)
{
ShelfView.Visibility = System.Windows.Visibility.Hidden;
CategoryView.Visibility = System.Windows.Visibility.Visible;
}
else if (sender == BookView)
{
BookView.Visibility = System.Windows.Visibility.Hidden;
ShelfView.Visibility = System.Windows.Visibility.Visible;
}
}
void ShelfView_BookSelected(object sender, EventArgs e)
{
BookView.Books = ShelfView.BookList;
ShelfView.Visibility = System.Windows.Visibility.Hidden;
BookView.Visibility = System.Windows.Visibility.Visible;
}
void CategoryView_CategorySelected(object sender, EventArgs e)
{
ShelfView.Category = CategoryView.ActiveCategory;
ShelfView.Visibility = System.Windows.Visibility.Visible;
CategoryView.Visibility = System.Windows.Visibility.Hidden;
ShelfView.RefreshBooks();
}
private void Grid_ManipulationStarting(object sender, ManipulationStartingEventArgs e)
{
//e.ManipulationContainer = this;
}
private void Grid_ManipulationDelta(object sender, ManipulationDeltaEventArgs e)
{
if (e.DeltaManipulation.Scale.X < 0)
{
if (ShelfView.Visibility == System.Windows.Visibility.Visible)
{
ShelfView.Visibility = System.Windows.Visibility.Hidden;
CategoryView.Visibility = System.Windows.Visibility.Visible;
}
else if (BookView.Visibility == System.Windows.Visibility.Visible)
{
BookView.Visibility = System.Windows.Visibility.Hidden;
ShelfView.Visibility = System.Windows.Visibility.Visible;
}
}
}
CATEGORYVIEW.XAML
<UserControl x:Class="SemanticZoom.Views.CategoryView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:s="http://schemas.microsoft.com/surface/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
<!--CATEGORY TEMPLATE-->
<DataTemplate x:Name="CategoryTemplate" x:Key="CategoryTemplate">
<s:SurfaceButton Background="Gray" Click="CategoryClicked" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Height="200" Width="300">
<TextBlock Text="{Binding Name}" TextWrapping="Wrap" Foreground="White" FontSize="20" FontWeight="Bold" />
</s:SurfaceButton>
</DataTemplate>
<!--CATEGORY STYLE-->
<Style TargetType="{x:Type s:SurfaceListBoxItem}">
<Setter Property="Width" Value="300"/>
<Setter Property="Height" Value="200"/>
</Style>
</UserControl.Resources>
<Grid>
<s:SurfaceListBox x:Name="CategoryList" ItemTemplate="{StaticResource CategoryTemplate}">
<s:SurfaceListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel IsItemsHost="True"
Height="{Binding ActualHeight, RelativeSource={RelativeSource AncestorType={x:Type ScrollContentPresenter}, Mode=FindAncestor}}"/>
</ItemsPanelTemplate>
</s:SurfaceListBox.ItemsPanel>
</s:SurfaceListBox>
</Grid>
Just don't judge me because a) yes I'm trying to emulate Semantic Zoom and b) yes I'm doing a hacky job of it. I just need a simple working concept. Each of the views is basically similar to CategoryView.

Answer 1

Thank you for your help Andriy, but it appears the problem was as simple as my monitor being far too insensitive. After I removed event hooks for all content on manipulation events, leaving only the hooks in the parent Grid, and then pressed VERY hard with two fingers on the screen, I got the events to fire. Probably need to mess a bit more with the routing, though.