UILongPressGestureRecognizer被激发了两次

当用户长时间按住地图超过2-4秒时，UILongPressGestureRecognizer被触发两次。 我怎样才能确保它只会被解雇一次？

func action(gestureRecognizer:UIGestureRecognizer) { println("long pressed on map") override func viewDidLoad() { super.viewDidLoad() manager = CLLocationManager() manager.delegate = self manager.desiredAccuracy = kCLLocationAccuracyBest if activePlace == -1 { manager.requestWhenInUseAuthorization() manager.startUpdatingLocation() } else { var uilpgr = UILongPressGestureRecognizer(target: self, action: "action:") uilpgr.minimumPressDuration = 2.0 myMap.addGestureRecognizer(uilpgr) } } func action(gestureRecognizer:UIGestureRecognizer) { println("long pressed on map") var touchPoint = gestureRecognizer.locationInView(self.myMap) var newCoordinate = myMap.convertPoint(touchPoint, toCoordinateFromView: self.myMap) var annotation = MKPointAnnotation() annotation.coordinate = newCoordinate //annotation.title = "New Place" myMap.addAnnotation(annotation) var loc = CLLocation(latitude: newCoordinate.latitude, longitude: newCoordinate.longitude) } 

Answer 1

您必须检查手势识别器的手势开始state ：

 func action(gestureRecognizer:UIGestureRecognizer) { if gestureRecognizer.state == UIGestureRecognizerState.Began { // ... } } 

Answer 2

长按手势是连续的。 当在指定的时间段（minimumPressDuration）按下允许的手指的数量（numberOfTouchesRequired）并且触摸不超过允许的移动范围（allowableMovement）时，手势开始（UIGestureRecognizerStateBegan）。 当手指移动时，手势识别器转换到改变状态，并且当任何手指抬起时手势识别器结束（UIGestureRecognizerStateEnded）。

尝试这样的事情：

 let longGesture = UILongPressGestureRecognizer(target : self, action : #selector(someFunc(gestureRecognizer:))) func someFunc(gestureRecognizer: UILongPressGestureRecognizer){ if gestureRecognizer.state == .began { //do something }