delphi怎样把子窗体显示在pagecontrol的tabsheet

https://bbs.csdn.net/topics/391980918

 unit Unit1;
 
 interface
 
 uses
   Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
   Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ComCtrls, Vcl.StdCtrls,
   Unit2;
 type
   TForm1 = class(TForm)
     Button1: TButton;
     Button2: TButton;
     Button3: TButton;
     PageControl1: TPageControl;
     TabSheet1: TTabSheet;
     procedure Button1Click(Sender: TObject);
   private
     { Private declarations }
   public
     { Public declarations }
   end;
 
 var
   Form1: TForm1;
   Form2: TForm2;
 implementation
 
 {$R *.dfm}
 
 procedure TForm1.Button1Click(Sender: TObject);
 begin
   if not Assigned(Form2) then
     Form2 := TForm2.Create(nil);
   try
     Form2.ManualDock(PageControl1.Pages[]);  // 嵌入PageControl1.Pages[0]
     Form2.Show;
   except
     Form2.Close;
     Exception.Create('Error');
   end;
 end;
 
 end.