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Getting Dragged RadtreeViewItems in DropQueryEvent

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DragAndDrop

This is a migrated thread and some comments may be shown as answers.

Akiono Wan asked on 06 Jan 2010, 09:03 AM

Hello,

I would like to evaluate wether a Drop Operation on a specfic RadtreeViewItem is allowed.
I got a WPF Radtreeview with hierachical Data Binding, Multiselection and Drag&Drop occurs only within the Treeview.
Therefore I added a Event Handler to the DropQuery Event of the RadTreeview.

    
            RadTreeView1.AddHandler(RadDragAndDropManager.DropQueryEvent, new EventHandler&lt;DragDropQueryEventArgs&gt;(RadTreeView_DropQuery), true);

For my Decision it is necessary to know which RadtreeviewItems are dragged. I don´t need the dragged data objects, because my decision is based on parent of each dragged RadtreeviewItem.

    
            private void RadTreeView_DropQuery(object sender, DragDropQueryEventArgs e) 
        
                    { 
        
                        bool dropPossible = checkIfDropPossible(draggedRadTreeViewItems); 
        
                        if (dropPossible) 
        
                        { 
        
                            e.QueryResult = true; 
        
                        } 
        
                        else 
        
                        { 
        
                            e.QueryResult = false; 
        
                        } 
        
            }

Therefore I need a way to get the dragged RadtreeviewItems in the DropQueryEvent. I searched all e.Options members but I get the responding data objects (e.Options.Payload) only.

How can I get corresponding dragged RadTreeViewItems to the DataObjects in the DropQueryEvent? Any help is welcome.

Best Regards
Akiono Wan

3 Answers, 1 is accepted

answered on 11 Jan 2010, 08:46 AM

Hi Valentin Stoychev,

thanks for your reply, but it doesn´t fit exactly to my problem.

With e.Options.Payload I will get my own datastructure. But I need the dragged RadTreeviewItem Objects and not my own datastructure.
Therefore I need a IEnumerable<RadtreeViewItem> draggedRadtreeviewItems.

I solved the problem by extending my own datastructure with a parent member property, but I think nevertheless it could be a suitable requirement to get the corresponding dragged RadtreeviewItems and not the own datastructure only.

Regards
Akiono Wan