GoDigram for .NET Framework and .NET Core
Northwoods.Go Namespace / GoView Class / DoExternalDrop Method
In This Topic
    DoExternalDrop Method
    In This Topic
    Handle drag-drops from another Control.
    Syntax
    protected virtual IGoCollection DoExternalDrop( 
       DragEventArgs evt
    )

    Parameters

    evt

    Return Value

    an IGoCollection holding the objects that were copied, if any, or null otherwise
    Remarks

    By default this method gets the drop data as a GoSelection, and copies the selected objects into this view's document with an offset that places the primary selection at the drop point. After calling GoDocument.CopyFromCollection to add a copy of each object in the selection to this view's document, it selects all of them in this view and raises an event by calling RaiseExternalObjectsDropped.

    This method is commonly overridden in order to handle different data formats, depending on the expected actual source Control.

    This method is called by OnDragDrop normally if IsInternalDragDrop is false, but will also be called by OnDragEnter if ExternalDragDropsOnEnter is true. In the latter case, the view's Selection should be the newly dropped objects created by this method. The selection is built between SelectionStarting and SelectionFinished events.

    After the GoObjects have been created and added to the document as part of the drop and after those objects have been selected, and when ExternalDragDropsOnEnter is false, this method checks the value of DoSelectionDropReject to see if it the drop is permitted or should be cancelled. If it should be cancelled, the selection is deleted. Otherwise, this method calls DoSelectionDropped and then RaiseExternalObjectsDropped.

    See Also