[NumLock]

Код:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls;

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    AShape: TShape;
    procedure ShapeMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
  public
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.ShapeMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  ShowMessage('ShapeMouseDown');
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  AShape:=TShape.Create(Self);
  AShape.Parent:=Self;
  AShape.OnMouseDown:=ShapeMouseDown;
end;

end.