How to Display Hierarchical Data

RadPanelBarItem inherits from HeaderedItemsControl therefore it can display hierarchical data, e.g. collections that contain other collections.

The HierarchicalDataTemplate class is designed to be used with HeaderedItemsControl types to display such data. There should be virtually no differences between the usage of HierarchicalDataTemplate in RadPanelBar and other controls.

The following example demonstrates how to create a hierarchical data source and bind a RadPanelBar to it, using a HierarchicalDataTemplate. The ItemsSource property of the HierarchicalDataTemplate specifies the binding that has to be applied to the ItemsSource property of each item. The DataTemplate property specifies the template that has to be applied on each item, while the ItemTemplate is the template applied on its child items.

1. Create a new class and name it MyViewModel:

       public class MyViewModel 
       { 
           public MyViewModel() 
           { 
               this.RelatedItems = new ObservableCollection<object>(); 
           } 
           public string Title { get; set; } 
           public DateTime DateCreated { get; set; } 
           public double Price { get; set; } 
           public IList<object> RelatedItems { get; set; } 
       } 
   

       Public Class MyViewModel 
           Public Sub New() 
               Me.RelatedItems = New ObservableCollection(Of Object)() 
           End Sub 
           Public Property Title() As String 
               Get 
                   Return _Title 
               End Get 
               Set(ByVal value As String) 
                   _Title = value 
               End Set 
           End Property 
           Private _Title As String 
           Public Property DateCreated() As DateTime 
               Get 
                   Return _DateCreated 
               End Get 
               Set(ByVal value As DateTime) 
                   _DateCreated = value 
               End Set 
           End Property 
           Private _DateCreated As DateTime 
           Public Property Price() As Double 
               Get 
                   Return _Price 
               End Get 
               Set(ByVal value As Double) 
                   _Price = value 
               End Set 
           End Property 
           Private _Price As Double 
           Public Property RelatedItems() As IList(Of Object) 
               Get 
                   Return _RelatedItems 
               End Get 
               Set(ByVal value As IList(Of Object)) 
                   _RelatedItems = value 
               End Set 
           End Property 
           Private _RelatedItems As IList(Of Object) 
       End Class 
   

   The class has four properties:

   • Property Price which is of type double.

   • Property CreatedOn which is of type DateTime.

   • Property Title which is of type string.

   • Property RelatedItems which is a collection of objects. These are the child items. Add a static method to the class which aims to create some mock-up data:

             public static IList<object> GenerateItems() 
             { 
                 var result = new ObservableCollection<object>(); 
                 foreach (var num in Enumerable.Range(1, 5)) 
                 { 
                     var item = new MyViewModel(); 
                     item.DateCreated = DateTime.Today.AddDays(-num % 15); 
                     item.Price = num * 100 + Convert.ToDouble(num) / 100; 
                     item.Title = String.Format("Item {0}", num); 
                     for (int i = 0; i < 5; i++) 
                     { 
                         var child = new MyViewModel(); 
                         child.DateCreated = DateTime.Today.AddDays(-num % 5 - i); 
                         child.Price = num * 100 + Convert.ToDouble(num + i) / 100; 
                         child.Title = String.Format("Item {0}.{1}", num, i); 
                         item.RelatedItems.Add(child); 
                     } 
                     result.Add(item); 
                 } 
                 return result; 
             } 
     

             Public Shared Function GenerateItems() As IList(Of Object) 
                 Dim result = New ObservableCollection(Of Object)() 
                 For Each num In Enumerable.Range(1, 5) 
                     Dim item = New MyViewModel() 
                     item.DateCreated = DateTime.Today.AddDays(-num Mod 15) 
                     item.Price = num * 100 + Convert.ToDouble(num) / 100 
                     item.Title = [String].Format("Item {0}", num) 
                     For i As Integer = 0 To 4 
                         Dim child = New MyViewModel() 
                         child.DateCreated = DateTime.Today.AddDays(-num Mod 5 - i) 
                         child.Price = num * 100 + Convert.ToDouble(num + i) / 100 
                         child.Title = [String].Format("Item {0}.{1}", num, i) 
                         item.RelatedItems.Add(child) 
                     Next 
                     result.Add(item) 
                 Next 
                 Return result 
             End Function 
     

2. Declare a HierarchicalDataTemplate

       <UserControl.Resources> 
           <DataTemplate x:Key="PanelBarItemTemplate"> 
               <StackPanel> 
                   <TextBlock Text="{Binding Title}"/> 
                   <TextBlock Text="{Binding DateCreated}"/> 
                   <TextBlock Text="{Binding Price}"/> 
               </StackPanel> 
           </DataTemplate> 
    
           <HierarchicalDataTemplate x:Key="PanelBarHeaderTemplate" 
                                      ItemsSource="{Binding RelatedItems}" 
                                      ItemTemplate="{StaticResource PanelBarItemTemplate}"> 
               <TextBlock Text="{Binding Title}" /> 
           </HierarchicalDataTemplate> 
       </UserControl.Resources> 
   

3. Define the RadPanelBar and set its ItemTemplate property

       <telerik:RadPanelBar x:Name="radPanelBar" Width="200"  
                      HorizontalAlignment="Center" VerticalAlignment="Top" 
                      ItemTemplate="{StaticResource PanelBarHeaderTemplate}"> 
       </telerik:RadPanelBar> 
   

4. Set the ItemsSource property of the RadPanelBar

       this.radPanelBar.ItemsSource = MyViewModel.GenerateItems(); 
   

   Me.radPanelBar.ItemsSource = MyViewModel.GenerateItems()