Why does my custom DragObject not function?

Applies to:
ExpressQuantumGrid 3, ExpressQuantumTreeList 3, ExpressInspector, stand-alone editors (ExpressEditors Library 3)
ExpressQuantumGrid 4 and 5, ExpressQuantumTreeList 4, ExpressVerticalGrid, stand-alone editors (ExpressEditors Library 4 and 5)

By design, our controls require the TDragControlObject component to be used. So, you should derive your custom DragObject from this class.

NOTE: When using CX controls (ExpressQuantumGrid 4 and 5, ExpressQuantumTreeList 4, ExpressVerticalGrid, stand-alone editors (ExpressEditors Library 4 and 5)) it is best to derive your DragObject from the TcxDragControlObject (cxControls.pas) that is itself inherited from the TDragControlObject.

Please refer to the "How to drag a cell's value to an external editor" article for a sample of a custom DragObject for the ExpressQuantumGrid 4.

See also:
How to implement drag-and-drop using ExpressQuantumGrid 4
How to implement drag-and-drop inside a Grid
How to obtain the Grid row at a given location on the screen
How to allow an end-user to perform a drag and drop operation with a specific criteria