Dropping from external Controls

Hi, I’m new at GoDiagram. I have a question concerning the Drag and Drop from en external Control (Windows.Forms.TreeView).
The problem is not to drop an object just into the GoView, which works fine. I want to be able to drop direct “into” another GoObject, which is already in the document. This object contains a GoGroup. I can Drag and Drop objects from the view into this object by overriding “SelectionDropped”. In short : take an object from the (external) TreeView and drop it “into” an object in the document.
Thanks for your help,

The Planogrammer sample application demonstrates this.
You’ll see that in Planogrammer, the Display class (which inherits from GoGroup) overrides GoObject.OnSelectionDropped to add Items to the Display.
The GoView has turned on the properties DragsRealtime and ExternalDragDropsOnEnter, so that a drag-and-drop from any Control will actually create GoObject(s) and add them to the GoDocument. This allows them to be selected and dragged around by the GoToolDragging tool and to participate in GoView.ObjectEnterLeave, ObjectSelectionDropReject, and ObjectSelectionDropped events (which includes calling the corresponding GoObject methods as event handlers).

Thanks for the answer, but I have still the problem, that the GoToolDraggint tool isn’t the active one if I’m dragging from a Windows.Forms.TreeView for example. I set the DragsRealtime and ExternalDragDropsOnEnter Properties of the view true, but in the OnEnterLeave, the active tool is the GoToolManager.
Do I have to activate the dragging tool at some point before?
In the Planogrammer example, the EventHandler “OnEnterLeave” doesn’t work too, if you try to drag something from the TreeView. but after activating/implementing the “TreeView.ItemDrag”, setting the view.tool to a new draggingTool and adding an item to the view.document and view.selection it works. But that isn’t a good solution for the problem I think.

GoView.ObjectEnterLeave events are also raised by GoToolManager when there is no dragging nor any other tool operating. To see if a drag is in progress you can look at the GoView.Tool to see if it is a GoToolDragging.
The point of GoView.ExternalDragDropsOnEnter is that it will convert an external drag-and-drop into a drop (causing GoView.Selection to be the newly created GoObject(s)) and an internal drag (using GoToolDragging). This sounds very much like what you say you have already done manually in your last paragraph. However, I don’t understand why you don’t think it’s a good solution.