ios - 为什么UILongPressGestureRecognizer返回两次

下面的代码似乎打印了两次值，即使我按住2秒。
不管我换成什么样的持续时间，似乎总是要执行两次，有人知道为什么会这样吗？

func action(gestureRecognizer:UIGestureRecognizer){
    var touchPoint = gestureRecognizer.locationInView(self.myMap);
    var newCo = myMap.convertPoint(touchPoint, toCoordinateFromView: self.myMap);
    var annotation = MKPointAnnotation();
    annotation.coordinate = newCo;
    var loc = CLLocation(latitude: newCo.latitude, longitude: newCo.longitude);
            CLGeocoder().reverseGeocodeLocation(loc, completionHandler: {(placemarks, error)->Void in
        let pm:CLPlacemark = placemarks[0] as CLPlacemark;

        var address = pm.locality + " ," + pm.postalCode + " ," + pm.administrativeArea + " ," + pm.country;
        annotation.title = address;
        self.myMap.addAnnotation(annotation);
        println(address);
        println("\(newCo.latitude)");
        println("\(newCo.longitude)");
        //places.append(["name:":address, "lat": "\(newCo.latitude)", "lon":"\(newCo.longitude)"]);
    })


}

最佳答案

检查UIGestureRecognizer的state属性，可能会同时得到begin和end。

enum UIGestureRecognizerState : Int {
    case Possible
    case Began
    case Changed
    case Ended
    case Cancelled
    case Failed
}