SendMessage(Form2.Handle, WM_NCACTIVATE, Ord(True), 0);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  Form2.Close;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  //记得加上这一句
  if Form2.Showing then Form2.Close;
end;

end.