UILongPressGestureRecognizer被解雇两次

Question

当用户长时间按下地图超过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

你必须检查手势recognizer's state的开始姿势：

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）。手指移动时，手势识别器转换到“更改”状态，并且当任何手指抬起时手势识别器结束（UIGestureRecognizerStateEnded）。

尝试这样：

let longGesture = UILongPressGestureRecognizer(target : self, 
action : #selector(someFunc(gestureRecognizer:))) 


func someFunc(gestureRecognizer: UILongPressGestureRecognizer){ 
if gestureRecognizer.state == .began { 
//do something 
}