从graphiccontrol继承,就是想画一矩形,哪儿错啦????

Question

unit Unit2;interface
uses
   Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs;
type
  TMyDrawing=class(tgraphiccontrol)
  private
    FColor:tcolor;
    procedure setcolor(value:tcolor);
  protected
    procedure paint;override;
  published
    property  color  read fcolor  write setcolor;
  public
     constructor Create(AOwner: TComponent);OVERRIDE;
     property canvas;
  end;
implementation
  constructor tmydrawing.create(AOwner: TComponent);
  begin
    inherited create(aowner);
    width:=100;
    height:=100;
    fcolor:=clred;
  end;
  procedure tmydrawing.paint;
var
 aa:integer;
 bb:integer;
  begin
   Canvas.Pen.width:=1;
   Canvas.Pen.Color:=fcolor;
   aa:=left+width;
   bb:=top+height;
   canvas.Rectangle(left,top,aa,bb);
  end;  procedure tmydrawing.setcolor(value:tcolor);
  begin
     fcolor:=value;
  end;
end.

Answer 1

property  color  read fcolor  write setcolor;
------------------------------------------------  
property  color:TColor read fcolor write setcolor;