let singleTap = UITapGestureRecognizer(target: self, action: #selector(DemoController7.stopWattingCircle))
singleTap.numberOfTapsRequired = 1
singleTap.numberOfTouchesRequired = 1
//self.view.userInteractionEnabled = true
//self.view.multipleTouchEnabled = true
self.waittingCircle?.addGestureRecognizer(singleTap)
注意这里是:#selector(DemoController7.stopWattingCircle))