Self referencing hierarchy RowLoaded event on Child Table Definitions

[Russ]

I've been working on an application using a multi-level self-referencing heirarchy, and have come across a problem with using the RowLoaded event for any level other than the first level.  Hopefully someone can give me a pointer on how to get this working. 

My basic goal at the moment is to disable the expand button (+) next to items that do not have a heirarchy beneath them,  I've recreated the sample from here in WPF, as a simple baseline.   I've added a little to this to try to make it work as I need (including only having heirarchies related to some items),  So I'll post my version of the code below.   As I mentioned, I'm using the RowLoaded event to decide whether or not to make the row expandable, but this only works for the first level. 

Is there a way I  can use this RowLoaded event (or another one) to do the same for levels 2 - 10 (or however deep it goes)?

Thanks,
Russell

The MainWindow.xaml:

<Window x:Class="HeirarchicalGridExample.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:telerikGrid="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.GridView"
        xmlns:telerikData="clr-namespace:Telerik.Windows.Data;assembly=Telerik.Windows.Data"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <telerikGrid:RadGridView x:Name="RadGridView1" ItemsSource="{Binding}" DataLoading="RadGridView1_DataLoading" RowLoaded="RadGridView1_RowLoaded" />
    </Grid>
</Window>

The MainWindow.xaml.cs:

using System;
using System.Collections.Generic;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Data;
using Telerik.Windows.Controls.GridView;
using Telerik.Windows.Controls;
using Telerik.Windows.Data;

namespace HeirarchicalGridExample
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            DataContext = from i in Enumerable.Range(0, 5)
                          select new MyObject()
                          {
                              ID = i,
                              Name = String.Format("Name{0}", i),
                              Level = 1
                          };
        }

        public class MyObject
        {
            public int ID { get; set; }
            public string Name { get; set; }
            public int Level { get; set; }

            public IEnumerable<MyObject> Items
            {
                get
                {
                    if (ID == 1 || ID == 3 || ID == 5 || ID == 7)
                    {
                        return from i in Enumerable.Range(0, 10)
                               select new MyObject()
                               {
                                   ID = i,
                                   Name = String.Format("{0}", Name + " - " + i.ToString()),
                                   Level = Level + 1
                               };
                    }
                    else
                        return Enumerable.Empty<MyObject>();
                }
            }
        }

        private void RadGridView1_DataLoading(object sender, Telerik.Windows.Controls.GridView.GridViewDataLoadingEventArgs e)
        {
            var grid = (GridViewDataControl)sender;

            var d = new GridViewTableDefinition();
            d.Relation = new PropertyRelation("Items");
            grid.TableDefinition.ChildTableDefinitions.Add(d);

            grid.AutoGenerateColumns = false;
            grid.Columns.Add(new GridViewDataColumn() { DataMemberBinding = new Binding("Level") });
            grid.Columns.Add(new GridViewDataColumn() { DataMemberBinding = new Binding("ID") });
            grid.Columns.Add(new GridViewDataColumn() { DataMemberBinding = new Binding("Name") });
        }

        // this is only working for the top level of the grid
        private void RadGridView1_RowLoaded(object sender, RowLoadedEventArgs e)
        {
            GridViewRow row = e.Row as GridViewRow;
            MyObject rowItem = e.DataElement as MyObject;

            if (row != null && rowItem != null)
            {
                if (rowItem.Items.Count<MyObject>() > 0)
                    row.IsExpandable = true;
                else
                    row.IsExpandable = false;
            }
        }
    }
}

[Veselin Vasilev]

Hello Russ,

Yes, that is right. The RowLoaded event fires for the parent gridview only. If you need that event for the child (nested) grids you need to define a HierarchyChildTemplate, place a gridview inside it and subscribe to its RowLoaded event.

I am attaching a sample project here - hope it will help you.

Regards,
Veskoni
the Telerik team

[Russ]

Yes, Thank you.  I've just gone through your example and that seems to be exactly what I'm looking for.

Thanks for the help.

Russell.