请高手帮我个忙，关于 DLL 创建组件的，有源码 ( 积分: 50 )

library Project1;

uses
SysUtils, Controls, Stdctrls, Extctrls, Windows, Graphics, Classes, Forms;
{$R *.res}

function CreateControl(AParent : TWinControl; AOwner : TComponent) : THandle; stdcall; export;
var
c : TPanel;
begin
c := TPanel.Create(AOwner);
c.Parent := AParent;
c.SetBounds(10, 10, 300, 200);
c.Visible := true;
Result := 1;
end;

exports
CreateControl;
begin
end.

//调用程序
var
ret : Integer;

function CreateControl(AParent : TWinControl; AOwner : TComponent) : THandle; stdcall; external 'project1.dll';

procedure TForm1.Button1Click(Sender: TObject);
begin
c := CreateControl(panel1, panel1);
end;

调用成功，为什么显示不出来？非得要 ShowWindow 函数，但用了这个函数后，程序里就乱了，应该失去焦点的不失去！