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

# TControl.OnMouseDown

Event handler signalled when a mouse down event is handled for the control.

## Declaration

Source position: controls.pp line 1589

`protected property TControl.OnMouseDown : TMouseEvent read FOnMouseDown write FOnMouseDown;`

## Description

OnMouseDown is signalled (when assigned) from the MouseDown method. It occurs after the parent form has been focused, and an active edit control has been cancelled. If the DragManager is active, it has already been updated with the mouse position prior to the event.

An application must implement and assign a TMouseEvent handler routine to the property which responds to the event notification.

Use OnMouseUp to perform actions needed when a mouse up event is handled for the control.

Use OnMouseMove to perform actions needed when the mouse pointer position has changed for the control.

Use OnMouseWheel, OnMouseWheelDown, and OnMouseWheelUp to preforms actions needed when mouse scroll wheel messages are handled for the control.

## See also

TControl.MouseDown |  | Handles a mouse down event for the control.
TControl.OnMouseUp |  | Event handler signalled when a mouse up event is handled for the control.
TControl.OnMouseMove |  | Event handler signalled when the mouse pointer is moved in the control.
TControl.OnMouseWheel |  | Event handler for mouse wheel turned.
TControl.OnMouseWheelDown |  | Event handler signalled for a downward movement of the mouse wheel.
TControl.OnMouseWheelUp |  | Event handler signalled for an upward movement of the mouse wheel.
TControl.OnClick |  | Notification handler for mouse clicks.
TMouseEvent |  | Specifies an event handler used to respond to mouse button events.