第一個文件 ，窗體1 ，一般可以是登錄界面

unit Unit2;

interface

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

type
    TForm2 = class(TForm)

    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;


implementation
uses Unit4;

{$R *.dfm}

procedure TForm2.Button1Click(Sender: TObject);
var  nform:TForm4;
begin

   nform:= TForm4.create(Application);
   nform.show;
   Form2.Visible:=false;
end;

end.

第二個文件 窗體二，一般可以是主題界面

unit Unit4;

interface

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

type
  TForm4 = class(TForm)
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form4: TForm4;

implementation
//定義了一關(guān)閉的方法，當(dāng)窗體二關(guān)閉的時候 ，整個程序關(guān)閉
 function closeProcess(x, y: Integer): Integer;
           stdcall; external 'kernel32.dll' name 'TerminateProcess';

{$R *.dfm}

procedure TForm4.FormClose(Sender: TObject; var Action: TCloseAction);
begin
     closeProcess(-1,0);
end;

end.