Drag and Drop freezing the application

[fred]

Hi the Telerik Team !

I'm having a strange behavior happening when I use the Drag and drop properties on items contained in a trewview.
My point is to be able to drag and drop a treeview item (that is contained for example in a folder) into another folder of the treeview.
 Normally simple
But when I do this, the silverlight project freezes totally, and if I close then open my widget again, it comes back still frozen, and I can't do anything else than rebooting the application.
I can't see what's freezing the application like this. If youcan give me a clue or a solution, please.
Here is my code.
Thanks in advance for the help :)

*---------------ConfigurationDragBehavior.cs-------------*
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 StormUI.Extensions.Inline;
using StormUI.Telerik.Extensions.DragAndDrop;
using Dashboard.Modules.Common.Objects;
using System.Collections.ObjectModel;

namespace ElementInformation.DragAndDropBehavior
{
    public class ConfigurationDragBehavior : InlineAction, ITelerikDragAndDropBehavior
    {
        bool IsAttached = false;

        ObservableCollection<LayoutField> Fields;

        protected override void Invoke(System.Collections.Generic.List<object> Parameters)
        {
            if (Parameters.Count > 0 && Parameters[0] is ObservableCollection<LayoutField>)
                Fields = Parameters[0] as ObservableCollection<LayoutField>;
        }

        void Attach(FrameworkElement element)
        {
            if (IsAttached == true)
                return;
            IsAttached = true;

            MBinding.FillBindings(Bindings);
            MBinding.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(MBinding_PropertyChanged);
            MBinding.BindedElement = element;
            MBinding.Update();
        }

        #region ITelerikDragAndDropBehavior Members

        public bool DragInfo(object sender, Telerik.Windows.Controls.DragDrop.DragDropEventArgs e)
        {
            Attach(sender as FrameworkElement);
            return true;
        }

        public void DragQuery(object sender, Telerik.Windows.Controls.DragDrop.DragDropQueryEventArgs e)
        {
            Attach(sender as FrameworkElement);
            e.QueryResult = true;
        }

        public bool DropInfo(object sender, Telerik.Windows.Controls.DragDrop.DragDropEventArgs e)
        {
            Attach(sender as FrameworkElement);
            if (e.Options.Source.DataContext is LayoutField && e.Options.Destination.DataContext is LayoutField && Fields.Contains(e.Options.Destination.DataContext as LayoutField))
            {
                if (e.Options.Status != Telerik.Windows.Controls.DragDrop.DragStatus.DropComplete)
                    return true;
                int index = Fields.IndexOf(e.Options.Destination.DataContext as LayoutField);
                Fields.Remove(e.Options.Source.DataContext as LayoutField);
                Fields.Insert(index, e.Options.Source.DataContext as LayoutField);
            }
            return false;
        }

        public void DropQuery(object sender, Telerik.Windows.Controls.DragDrop.DragDropQueryEventArgs e)
        {
            Attach(sender as FrameworkElement);
            if (e.Options.Destination.DataContext is LayoutField && Fields.Contains(e.Options.Destination.DataContext as LayoutField))
                e.QueryResult = true;
        }

        #endregion
    }
}

*-----------------ConfigurationDropInfo.cs --------------*
using System;
using System.Linq;
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 Telerik.Windows.Controls.DragDrop;
using StormUI.Telerik.Extensions.DragAndDrop;
using System.Reflection;
using Hypercast.Proxy.Dashboard.Entities;
using Telerik.Windows.Controls.TreeView;
using StormUI.Extensions.Inline;
using System.Collections.Generic;
using Dashboard.Modules.Common.Objects;
using System.Collections.ObjectModel;

namespace ElementInformation.DragAndDropBehavior
{
    public class ConfigurationDropInfo : ITelerikDragAndDropBehavior
    {
        #region ITelerikDragAndDropBehavior Members

        public bool DragInfo(object sender, DragDropEventArgs e)
        {
            return true;
        }

        public void DragQuery(object sender, DragDropQueryEventArgs e)
        {
            e.QueryResult = true;
        }


        public bool DropInfo(object sender, DragDropEventArgs e)
        {
            TreeViewDragCue dragcue = e.Options.DragCue as TreeViewDragCue;

            if (e.Options.Source.DataContext is Type)
                RadDragAndDropManager.CancelDrag();
            if (e.Options.Source.DataContext is PropertyInfo)
            {
                PropertyInfo property = e.Options.Source.DataContext as PropertyInfo;
                if (e.Options.Destination.Tag as string == "SEARCH")
                {
                    bool IsSearchable = (bool)TypeGenerator.GetAttributeValue(property, TypeGenerator.SearchableAttribute).FirstOrDefault();
                    if (dragcue != null)
                        dragcue.IsDropPossible = IsSearchable;
                    return IsSearchable;
                }
                if (e.Options.Destination.Tag as string == "RESULT")
                {
                    bool IsVisible = (bool)TypeGenerator.GetAttributeValue(property, TypeGenerator.VisibleAttribute).FirstOrDefault();
                    if (dragcue != null)
                        dragcue.IsDropPossible = IsVisible;
                    return IsVisible;
                }
                if (dragcue != null)
                    dragcue.IsDropPossible = true;
                return true;
            }
            if (dragcue != null)
                dragcue.IsDropPossible = false;
            return false;
        }

        public void DropQuery(object sender, DragDropQueryEventArgs e)
        {
            TreeViewDragCue cue = e.Options.DragCue as TreeViewDragCue;
            if (e.Options.Status == DragStatus.DropDestinationQuery)
                cue.IsDropPossible = true;
            else
                cue.IsDropPossible = false;
            e.QueryResult = true;
        }

        #endregion
    }
}

*------------------------ListBoxDragBehavior.cs -**********************
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 StormUI.Telerik.Extensions.DragAndDrop;
using Telerik.Windows.Controls.DragDrop;
using System.Collections;
using System.Windows.Threading;
using System.Reflection;

namespace ElementInformation.DragAndDropBehavior
{
    public class ListBoxDragBehavior : ITelerikDragAndDropBehavior
    {
        DispatcherTimer _Timer;

        public ListBoxDragBehavior()
        {
            _Timer = new DispatcherTimer();
            _Timer.Interval = new TimeSpan(0, 0, 0, 0, 1);
            _Timer.Tick += new EventHandler(_Timer_Tick);
        }

        void _Timer_Tick(object sender, EventArgs e)
        {
            _Timer.Stop();
            RadDragAndDropManager.CancelDrag();
        }

        #region ITelerikDragAndDropBehavior Members

        public bool DragInfo(object sender, Telerik.Windows.Controls.DragDrop.DragDropEventArgs e)
        {
            if (e.Options.Status != DragStatus.DragCancel && (e.Options.Source.DataContext == null || e.Options.Source.DataContext is Type
                || (e.Options.Source.DataContext is PropertyInfo && typeof(IList).IsAssignableFrom((e.Options.Source.DataContext as PropertyInfo).PropertyType))))
            {
                _Timer.Start();
            }
            return true;
        }

        public void DragQuery(object sender, Telerik.Windows.Controls.DragDrop.DragDropQueryEventArgs e)
        {
        }

        public bool DropInfo(object sender, Telerik.Windows.Controls.DragDrop.DragDropEventArgs e)
        {
            return true;
        }

        public void DropQuery(object sender, Telerik.Windows.Controls.DragDrop.DragDropQueryEventArgs e)
        {
        }

        #endregion
    }
}

[Pavel Pavlov]

Hi fred,

I have not found anything disturbing in your code. Maybe the problem is related to the container you are using to host the controls. You said something about "widget" are you using popups, or windows host .. or something like that  ?

I can be in help further if you could send me your project. I will be glad to step over it locally and see what is causing the trouble.

Kind regards,
Pavel Pavlov
the Telerik team