code: def _watchdog_switch(self):
          
          # init
          self.current_controller = self.view_control_map['main']
          self.current_controller.run(self.switch_queue)
  
          while not self.quit_quit:
              key = self.switch_queue.get()
              if key == 'quit_quit':
                  self.quit_quit = True
              else:
                  self.current_controller = self.view_control_map[key]
                  self.current_controller.run(self.switch_queue)
  
          # 退出保存信息
          self.quit()
          os._exit(0)
docs: 切换页面线程