Drop Preview Lines not visible after upgrading to version 2011.3.1220.35

[Noushad]

Hi

Drop Preview Lines not visible on Radtreeview after upgrading to version 2011.3.1220.35.  It worked fine on previous version.
I tried the setting IsDropPreviewLineEnabled="True" but that does not make the Drop Preview Lines visible.  Any ideas on what may be causing this?

[Tina Stancheva]

Hi Noushad,

I wasn't able to reproduce the issue in a sample solution. Can you please have a look at the sample solution I attached and let me know if it works for you or if I've missed something? Thank you in advance.

Regards,
Tina Stancheva
the Telerik team

[Noushad]

Hi

The solution that you sent me does not allow me to drag and drop even so I cant verify whether or not the Drop Preview lines work.

Thank you for all your help.

[Tina Stancheva]

Hi Noushad,

This sample solution comes from our demo solutions for RadTreeView. It displays a list of staff in the left tree and new teams in the right tree. So you can expand the categories in the left RadTreeView to see the name of the employees and drag each employee into the right RadTreeView to place it in the appropriate team. This screencast shows the way the solution works on our side. Please have a look at it and let me know if I've missed something.

Greetings,
Tina Stancheva
the Telerik team

[Noushad]

Hi

Thanks for the screen cast.  I am familiar with the functionality of the rad tree view.  My application was working perfectly on a previous version of Telerik and after upgrading it now does not work exactly as it used to in the past.  Initially I had an issue where I couldn't drag and drop from a list box to the tree view but after adding < Setter Property="TelerikDragDrop:DragDropManager.AllowCapturedDrag" Value="True" /> it allowed me to drag. 

This is on Visual Studio 2008 and Dot Net Framework 3.5 SP1.  Dragging within the Rad treeview works its only the Drop Preview lines that are not visible.  The solution that you sent me I have tried running on a Windows 7, VS 2010, Dot Net Framework 4.0 and there it does not work.  Your solution is self contained so I cant think of what else may be causing the drag and drop not to work on this PC. 

I have tried it on another PC similar to mine and your solution works fine there.  Am I missing something?  

[Tina Stancheva]

Hi Noushad,

Can you confirm that on all machines where you've tried the solution, it uses the same version of the Telerik dlls?

Also, as the RadDragAndDropManager was changed with the 2011.2.712 version of the control, you can try setting the mode of the RadDragAndDropManager to DragExecutionMode.Legacy - this will use the old logic of the RadDragAndDropManager.

Please keep in mind that this property should be set before the initialization of the application's elements. This means that you can either set it in the App class constructor:

public App()
{
    RadDragAndDropManager.ExecutionMode = DragExecutionMode.Legacy;
}

or in the MainWindow constructor before calling the InitializeComponent method:

public MainWindow()
{
    RadDragAndDropManager.ExecutionMode = DragExecutionMode.Legacy;

    InitializeComponent();
}

Please let me know if that helps in getting over the issue.

Regards,
Tina Stancheva
the Telerik team