How to iterate over items in LibraryStack?

Question

I have the following LibraryStack definition:

<s:LibraryStack Name="TaggingContainer" Margin="20" Grid.Row="1" Grid.ColumnSpan="2" AllowDrop="True" Height="300" Width="300" s:SurfaceDragDrop.DragLeave="TaggingContainer_DragLeave" s:SurfaceDragDrop.DragEnter="TaggingContainer_DragEnter" s:SurfaceDragDrop.PreviewDrop="LibraryStack_PreviewDrop"> <s:LibraryStack.ItemTemplate> <DataTemplate> <Label Content="{Binding Name}" Tag="{Binding}" FontSize="20" Margin="10,10,10,10" HorizontalAlignment="Center" VerticalAlignment="Center" Foreground="White" Background="#c49b14" BorderBrush="White" BorderThickness="2" s:Contacts.PreviewContactDown="Label_PreviewContactDown"></Label> </DataTemplate> </s:LibraryStack.ItemTemplate> </s:LibraryStack> 

Now in encoding I want to iterate over all the labels that are contained in the LibraryStack (the label defined in the data template).

But if I use

 foreach (FrameworkElement element in TaggingContainer.Items) { } 

I iterate over data objects that are in a TaggingContainer, not Datatemplates. How to change this?

Answer 1

The easiest way is to find all LibraryStackItem or Label under LibraryStack in the visual tree. try it

 private void SomeMethod() { // Get All Labels List<Label> labels = GetVisualChildCollection<Label>(TaggingContainer); foreach (Label label in labels) { //... } } 

Alternatively, you can get a container for each element and get Label instead

 foreach (var element in TaggingContainer.Items) { LibraryStackItem libraryStackItem = TaggingContainer.ItemContainerGenerator.ContainerFromItem(element) as LibraryStackItem; Label label = VisualTreeHelpers.GetVisualChild<Label>(libraryStackItem); } 

GetVisualChild

 private static T GetVisualChild<T>(DependencyObject parent) where T : Visual { T child = default(T); int numVisuals = VisualTreeHelper.GetChildrenCount(parent); for (int i = 0; i < numVisuals; i++) { Visual v = (Visual)VisualTreeHelper.GetChild(parent, i); child = v as T; if (child == null) { child = GetVisualChild<T>(v); } if (child != null) { break; } } return child; } 

GetVisualChildCollection

 public static List<T> GetVisualChildCollection<T>(object parent) where T : Visual { List<T> visualCollection = new List<T>(); GetVisualChildCollection(parent as DependencyObject, visualCollection); return visualCollection; } private static void GetVisualChildCollection<T>(DependencyObject parent, List<T> visualCollection) where T : Visual { int count = VisualTreeHelper.GetChildrenCount(parent); for (int i = 0; i < count; i++) { DependencyObject child = VisualTreeHelper.GetChild(parent, i); if (child is T) { visualCollection.Add(child as T); } else if (child != null) { GetVisualChildCollection(child, visualCollection); } } }