[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'Controls' (#lcl)

# TControl.OnDragDrop

Event handler signalled when an object is dropped onto the control.

## Declaration

Source position: controls.pp line 1585

`protected property TControl.OnDragDrop : TDragDropEvent read FOnDragDrop write FOnDragDrop;`

## Description

OnDragDrop is a TDragDropEvent property with the event handler signalled when another control is dropped onto the control instance. Unlike with drag-dock, a default action is not associated with the drag-drop operation. The OnDragDrop handler is the only way to do something meaningful for the drag-drop operation.

The Sender argument contains the current control instance (Self) for for the event.

The Source argument is the object (TControl) which is droppped onto the current control instance.

X and Y contains the control-relative coordinates for the mouse pointer when the event occurred.

OnDragDrop is signalled from the DragDrop method, and occurs when dmDragDrop messages (TDragMessage) are handled for the control.

## See also

TControl.DragDrop |  | Signals the OnDragDrop handler when a dragged object is dropped onto this control.
TDragDropEvent |  | The type of an OnDragDrop notification handler.
TDragMessage |  | Message types used in DragManager.