[Solved] LoadOnDemand for a collection based on a DependencyProperty

[Matthew Cartwright]

Hi,

My first level collection is an ObservableCollection stored as a DependencyProperty in my usercontrol. This collection has sub-properties that contain the child collections. Using the example in the (offline) help file I have a WCF service being called to load the 2nd level of items OnDemand.

        public ObservableCollection<Batch> Batches
        {
            get { return (ObservableCollection<Batch>)GetValue(BatchesProperty); }
            set { SetValue(BatchesProperty, value); }
        }
        public static readonly DependencyProperty BatchesProperty =
            DependencyProperty.Register("Batches", typeof(ObservableCollection<Batch>), typeof(MyTreeView), new PropertyMetadata(null, BatchesChanged));
        public static void BatchesChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
        {
            // not doing anything in the callback

        }

But, because the treeview is bound to the DependencyProperty, the UI is not getting updated when the sub-collection is added.

Does anyone have an example of this working?

Thanks,
Matt

[Matthew Cartwright]

This was caused by an problem in the CHM help file. The following XAML is specified for the HierarchicalDataTemplate:

<DataTemplate x:Key="ProductTemplate">
   <TextBlock Text="{Binding ProductName}" />
</DataTemplate>
<telerik:HierarchicalDataTemplate x:Key="CategoryTemplate" ItemsSource="{Binding Products}"
 ItemTemplate="{StaticResource ProductTemplate}">
   <TextBlock Text="{Binding CategoryName}" />
</telerik:HierarchicalDataTemplate>
<HierarchicalDataTemplate x:Key="CategoryTemplate" ItemsSource="{Binding Products}"
   ItemTemplate="{StaticResource ProductTemplate}">
   <TextBlock Text="{Binding CategoryName}" />
</HierarchicalDataTemplate>

I had incorrectly taken out the telerik:HierarchicalDataTemplate, instead remove the standard HierarchicalDataTemplate