UILongPressGestureRecognizer在MapKit（适配器）中失效问题排查

我通过适配器对象在视图控制器中使用MapKit，给大头针视图（PinView）同时添加了长按和点击手势，但仅长按手势无法触发，点击手势正常工作。相关代码如下：

手势准备代码 #

private func prepareGestures(on pinView: PinViewProtocol) {
    let longPressGesture = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPress(sender:)))
    longPressGesture.delegate = self
    longPressGesture.minimumPressDuration = Constants.longPressDuration
    
    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(sender:)))
    tapGesture.delegate = self
    
    pinView.addGestureRecognizers([tapGesture, longPressGesture])
}

手势添加逻辑 #

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    guard let annotation = annotation as? MyPinAnnotation else {
        return nil
    }
    prepareGestures(on: pinView)
    return pinView
}

适配器配置代码 #

private func configureMapView() {
    mapViewAdapter = TestMapViewAdapter(mapView: mapView)
}

解决方案 #

1. 处理手势识别冲突

点击手势的响应优先级高于长按，会提前拦截触摸事件导致长按无法触发。通过手势代理调整识别规则：

extension TestMapViewAdapter: UIGestureRecognizerDelegate {
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        // 允许长按与点击手势同时识别
        return gestureRecognizer is UILongPressGestureRecognizer && otherGestureRecognizer is UITapGestureRecognizer
    }

    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        // 让点击手势等待长按手势失败后再触发
        return gestureRecognizer is UITapGestureRecognizer && otherGestureRecognizer is UILongPressGestureRecognizer
    }
}

2. 移除MapKit默认长按手势干扰

MKMapView自带长按手势用于添加系统大头针，会和自定义手势冲突。在适配器初始化时移除系统手势：

init(mapView: MKMapView) {
    self.mapView = mapView
    // 移除系统默认长按手势
    mapView.gestureRecognizers?.removeAll(where: { $0 is UILongPressGestureRecognizer })
}

3. 确保视图交互开启

确认PinViewProtocol对应的视图类已开启用户交互（虽然点击生效大概率已开启，但需验证）：

class PinView: MKAnnotationView, PinViewProtocol {
    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        self.isUserInteractionEnabled = true
    }
}

4. 修正手势添加时机

避免在视图复用时重复添加手势，仅在首次创建视图时添加：

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    guard let annotation = annotation as? MyPinAnnotation else {
        return nil
    }
    let reuseId = "MyPinAnnotation"
    var pinView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseId) as? PinViewProtocol
    if pinView == nil {
        pinView = PinView(annotation: annotation, reuseIdentifier: reuseId)
        prepareGestures(on: pinView!)
    }
    pinView?.annotation = annotation
    return pinView as? MKAnnotationView
}

内容的提问来源于stack exchange，提问作者Kaan Vural