自定义组件怎么不显示caption

Question

小弟刚开始学开发组件,帮忙看一下，怎么控件上没有显示caption
unit btn;interfaceuses
  SysUtils, Classes, Controls,dialogs,windows,forms,extctrls,messages,graphics;type
  tbtn = class(TCustomControl)
  private
    fbordercolor: tcolor;
    fform:tform;
    ffont:tfont;    fcaption: tcaption;
    procedure setbordercolor(Value: tcolor);
    procedure setfont(Value: tfont);
    procedure setcaption(const Value: tcaption);
    { Private declarations }
  protected
    { Protected declarations }  public
    { Public declarations }
    procedure paint;override;
    constructor create(aowner:tcomponent);override;
  published
    { Published declarations }
    property width;
    property caption:tcaption read fcaption write setcaption;
    property ondblclick;
    property font:tfont read ffont write setfont;
    property bordercolor:tcolor read fbordercolor write setbordercolor;
  end;procedure Register;
var
    editrect:trect;
implementationprocedure Register;
begin
  RegisterComponents('haoge', [tbtn]);
end;{ tbtn }constructor tbtn.create(aowner: tcomponent);
begin
  inherited create (aowner);
  fform:=tform(owner);
  ffont:=tfont.Create();
end;procedure tbtn.paint;
var r:trect;
    textl,textt:integer;
begin
    r:=clientrect;
    frame3d(canvas,r,fbordercolor,fbordercolor,1);
  inherited;
end;procedure tbtn.setbordercolor(Value: tcolor);
begin
  fbordercolor := Value;
  repaint;
end;procedure tbtn.setcaption(const Value: tcaption);
begin
  fcaption := Value;
end;procedure tbtn.setfont(Value: tfont);
begin
  ffont := Value;
end;end.

Answer 1

修改如下：  自己看一下，
procedure tbtn.setcaption(const Value: tcaption); 
begin 
  fcaption := Value; 
Invalidatel;
end; 

Answer 2

不行啊，控件上还是没有显示caption的内容