如何在某人未点击视图的视图上添加观察者

Question

  // 1.create UIView  
     *lazy var  handleVedioView:UIView = {
        let view = UIView()
        return view    //returning view
      }()

 //adding observer to my view
     view.addObserver(self, forKeyPath: <#T##String#>, options: .new, context:nil)

 *//executing closure block