Treeview nodes looking strange after drag and drop

[Ole]

Hi,

I have a treeview hooked up to an oberserverble collection and a hieracical template.

I am working on drag and drop in the treeview.  How ever when dragging node  test 011 .... up under   test 001...  (see treeview1) , and toggle the node expanders I get (treeview2a) , where it correctly has been removed from it source node, but only a white space has come on its destination node. clicking the whitespace make a dotted line around the root level node. I have checked in the code behind and verified that the parent node(test00test....) has the correct child nodes in its children property.

Also when   dragging a treenode inside another treenode there is a problem. Going from treeview3 to treeview4 you see that it looks like the dragged node gets put under the existing ones.Also here I have to toggle the expand nodes.

my relevent code  is,

<Grid.Resources>

<!--<local:PriceAreaListProvider x:Key="priceAreaListProvider" />-->


<telerik:HierarchicalDataTemplate x:Key="NodeTemplate" ItemsSource="{Binding Children}">

<StackPanel Orientation="Horizontal">

<TextBlock Text="{Binding Heiti}" TextWrapping="Wrap" MouseLeftButtonDown="TextBox_MouseLeftButtonDown" />

<TextBlock Text="{Binding Heiti_e}" TextWrapping="Wrap" />

</StackPanel>

</telerik:HierarchicalDataTemplate>

</Grid.Resources>

<telerik:RadTreeView Width="220" Grid.Row="2"  HorizontalAlignment="Left"   HorizontalContentAlignment="Left" x:Name="TreeView1"   VerticalAlignment="Top"  ItemTemplate="{StaticResource NodeTemplate}" ScrollViewer.HorizontalScrollBarVisibility="Auto" ScrollViewer.VerticalScrollBarVisibility="Auto" MaxHeight="570"  IsExpandOnSingleClickEnabled="True" SelectedValuePath="Heiti" IsEditable="True" Edited="TreeView1_Edited" IsDragDropEnabled="True" DragEnded="TreeView1_DragEnded">
           <telerik:RadTreeView.ItemEditTemplate>
               <DataTemplate>
                   <StackPanel Orientation="Horizontal">
                       <TextBox Text="{Binding Heiti, Mode=TwoWay}" />
                       <TextBox Text="{Binding Heiti_e, Mode=TwoWay}" />
                   </StackPanel>
               </DataTemplate>
           </telerik:RadTreeView.ItemEditTemplate>
       </telerik:RadTreeView>

private void CostPlanInfoGridView_SelectionChanged(object sender, SelectionChangeEventArgs e)
        {
            if (CostPlanInfoGridView.SelectedItem!=null)
            {
                basicContext.tbl_KostKaflars.Clear();
                TreeView1.ItemsSource = new HierarchicalDataSourceCustomsChapters(basicContext, ((tbl_KostAaetlun)CostPlanInfoGridView.SelectedItem).ID);
            }

        }

private void TreeView1_DragEnded(object sender, RadTreeViewDragEndedEventArgs e)
       {
           System.Collections.ObjectModel.Collection<object> col = e.DraggedItems;
           tbl_KostKaflar target = (tbl_KostKaflar) e.TargetDropItem.Item;
           tbl_KostKaflar droppedItem = (tbl_KostKaflar)col.First();
           //adjust rod in sieblings in the chapter it was dragged from.
           List<tbl_KostKaflar> rodadjustListPrev = basicContext.tbl_KostKaflars.Where(t => t.parentID == droppedItem.parentID && t.Rod > droppedItem.Rod).ToList();
           foreach (tbl_KostKaflar item in rodadjustListPrev)
           {
               item.Rod--; //
           }

           tbl_KostKaflar PreviousParentKaflar = basicContext.tbl_KostKaflars.Where(t => t.ID == droppedItem.parentID).First();
           //PreviousParentKaflar.Children.Remove(droppedItem);
           PreviousParentKaflar.Children.Sort(delegate(tbl_KostKaflar t1, tbl_KostKaflar t2) { return t1.Rod.CompareTo(t2.Rod); });
           if (PreviousParentKaflar.Children.Count==0)
           {
               PreviousParentKaflar.HasChild = false;
           }
           tbl_KostKaflar parentKaflar;
           if (e.DropPosition==DropPosition.Before)
           {
               List<tbl_KostKaflar> rodadjustList = basicContext.tbl_KostKaflars.Where(t => t.parentID == target.parentID && t.Rod > target.Rod).ToList();
               foreach (tbl_KostKaflar item in rodadjustList)
               {
                   item.Rod++; //
               }
               droppedItem.parentID = target.parentID;
               droppedItem.Rod = target.Rod;
               target.Rod++;
               parentKaflar = basicContext.tbl_KostKaflars.Where(t => t.ID == target.parentID).First();
           }
           else if (e.DropPosition==DropPosition.After)
           {
               droppedItem.Rod = target.Rod + 1;
               droppedItem.parentID = target.parentID;
               parentKaflar = basicContext.tbl_KostKaflars.Where(t => t.ID == target.parentID).First();
           }
           else
           {
               droppedItem.parentID = target.ID;
               droppedItem.Rod = target.Children.Count();
               parentKaflar = target;

           }



           //parentKaflar.Children.Add(droppedItem);
           parentKaflar.Children.Sort(delegate(tbl_KostKaflar t1, tbl_KostKaflar t2) { return t1.Rod.CompareTo(t2.Rod); });
           parentKaflar.HasChild = true;
           basicContext.SubmitChanges();
       }

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Collections.ObjectModel;
//using PriceBank.TreeViewService;
using System.Collections.Generic;
using System.Linq;
using PriceBank.Web.Services;
using System.ServiceModel.DomainServices.Client;
//using PriceBank.Web.DataModels;

namespace PriceBank
{
    public class HierarchicalDataSourceCustomsChapters : ObservableCollection<tbl_KostKaflar>
    {
        private List<tbl_KostKaflar> unsortedList = new List<tbl_KostKaflar>();
        private BuildingCostDomainContext buildContextGlb;
        public HierarchicalDataSourceCustomsChapters(BuildingCostDomainContext buildContext, int costplanID)
        {
            buildContextGlb = buildContext;
            buildContext.Load(buildContext.GetTbl_KostKaflarByCostPlanIdQuery(costplanID), priceContextLoaded, null);
        }

        private void priceContextLoaded(LoadOperation<tbl_KostKaflar> efni)
        {
            // transfer all the items from the result to the unsorted list
            foreach (tbl_KostKaflar item in efni.AllEntities)
            {
                //TableItem genericItem = new TableItem(item.Name,item.NodeId,item.ParentID,item.Path,item.WBSID,item.ChapterRanking,item.HasChild, buildContextGlb);
                this.unsortedList.Add(item);
            }

            // Get all the first level nodes. In our case it is only one - House M.D.

            var rootNodes = this.unsortedList.Where(x => x.parentID == 0);

            // Foreach root node, get all its children and add the node to the HierarchicalDataSource.
            // see bellow how the FindChildren method works
            foreach (tbl_KostKaflar node in rootNodes)
            {

                node.nodeLevel = 0;
                this.FindChildren(node);
                this.Add(node);
            }
        }

        private void FindChildren(tbl_KostKaflar item)
        {

            if (item.nodeLevel<2)
            {
                // find all the children of the item
                var children = unsortedList.Where(x => x.parentID == item.ID && x.ID != item.ID);
                if (item.Children == null)
                {
                    item.Children = new List<tbl_KostKaflar>();
                }
                // add the child to the item's children collection and call the FindChildren recursively, in case the child has children
                foreach (tbl_KostKaflar child in children)
                {
                    child.nodeLevel = item.nodeLevel + 1;

                    item.Children.Add(child);
                    FindChildren(child);
                }
            }

        }
    }
}

hope anyone can help!!

[Tina Stancheva]

Hello Ole,

Please accept my apology for the delayed response.

I reviewed the code snippet you sent and I noticed that the Children collection is a List collection. I suppose that the entire business collection displayed by the RadTreeView is a List collection.

However the drag/drop operations in the RadTreeView are trying to modify the ItemsSource collection and when the original business collection doesn't implement the INotifyPropertyChanged interface, the changes won't affect it thus causing the behavior you observed.

Therefore in order to use the DragAndDrop functionality of the RadTreeView you will need to use a collection that implements INotifyCollectionChanged, like ObservableCollection.

Please give this approach a try and let me know if it works for you.

Sincerely yours,
Tina Stancheva
the Telerik team

[Ole]

Hi,

Thank you for an answer well worth waiting for.


Best

Ole