Delphi7从入门到精通及附书源码 Delphi7从入门到精通及附书源码

				unit MWForm2;
				
				interface
				
				uses
				  Qt, SysUtils, Classes, QGraphics, QControls, QForms, QDialogs;
				
				type
				  TForm2 = class(TForm)
				    procedure FormClose(Sender: TObject; var Action: TCloseAction);
				  private
				    { Private declarations }
				  public
				    { Public declarations }
				  end;
				
				var
				  Form2: TForm2;
				
				implementation
				
				{$R *.xfm}
				
				procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
				begin
				  Action := caFree;
				  // important: set pointer to nil!
				  Form2 := nil;
				end;
				
				end.