调用DLL子窗体装入PAGECONTROL中的有关问题

求助调用DLL子窗体装入PAGECONTROL中的问题
library UDllFrom; //DLL庫封裝之處

{ Important note about DLL memory management: ShareMem must be the
  first unit in your library's USES clause AND your project's (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }

uses
  SysUtils,
  Classes,
  forms,
  RzTabs,
  UChildForm in 'UChildForm.pas' {Form1};

{$R *.res}
 procedure AddTabSheet(FormClass: TFormClass;tbs:TRZTabSheet; rzpgc:TRZPagecontrol);
 var
 Form:TForm;
begin
  rzpgc.ActivePage := tbs; //加上这一步算是双向指定了,指定激活页
  Form := FormClass.Create(tbs); //创建Form(用TabSheet)实例
  Form.Parent := tbs; //指定Form的父窗体
  tbs.Caption := Form.Caption; //标题
  tbs.TabVisible:=True;
  Form.Show; //显示
end;
function run_form(hs:THandle;tbs:TRZTabSheet;rzpgc:TRZPagecontrol):integer;stdcall;
var
 TForm1:TFormclass;
 begin
  Application.Handle:=hs;
  AddTabSheet(TForm1,tbs,rzpgc);
 end;
 exports
  run_form;
begin
end.
-----------------------------調用DLL窗體,將子窗体装入主窗体中
unit UTestForm;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, RzTabs, StdCtrls, Buttons;

type
  TTestForm = class(TForm)
  rzpgc: TRzPageControl;
  tbs: TRzTabSheet;
  BitBtn1: TBitBtn;
  procedure BitBtn1Click(Sender: TObject);
  private
  { Private declarations }
  public
  { Public declarations }
  end;
  function rum_Form(hs:THandle;tbs:TRZTabSheet;rzpgc:TRZPagecontrol):Integer;stdcall;external 'UDllFrom.dll';
var
  TestForm: TTestForm;

implementation

{$R *.dfm}

procedure TTestForm.BitBtn1Click(Sender: TObject);
begin
  rum_Form(Application.Handle,tbs,rzpgc);
end;

end.
----------------------------
提示錯誤,無法找到程序的輸入點


------解决方案--------------------
dll文件,TForm2为随便一个窗体
Delphi(Pascal) code

library Project1;

uses
  SysUtils,
  Classes,
  Controls,
  Forms,
  Windows,
  Unit2 in 'Unit2.pas' {Form2};

{$R *.res}
procedure ShowForm(app:TApplication; parent:TWinControl);stdcall;
var
  frm : TForm2;
begin
  frm := TForm2.Create(Application);
  frm.ParentWindow := parent.Handle;
  frm.Show;
  frm.Align := alClient;
end;

exports
  ShowForm name 'ShowForm';

begin

end.