Question

我有一个mapview，他的更新位置。因此，如果我正在移动我的定位不断更新。如果我拖动地图并尝试查看其他内容，我希望它停止。我怎么能这样做？

我尝试了这个解决方案，以检测拖动地图的时间： Determine if MKMapView was dragged/moved in Swift 2.0

我在swift3工作。

1：在viewDidLoad中添加手势识别器：

    let mapDragRecognizer = UIPanGestureRecognizer(target: self, action: Selector(("didDragMap:")))
    mapDragRecognizer.delegate = self
    self.map.addGestureRecognizer(mapDragRecognizer)

2：将协议UIGestureRecognizerDelegate添加到视图控制器，使其作为委托。

 class MapViewController: UIViewController, UIGestureRecognizerDelegate

添加了其他代码：

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}

  func didDragMap(gestureRecognizer: UIGestureRecognizer) {
if (gestureRecognizer.state == UIGestureRecognizerState.began) {
    print("Map drag began")
  self.locationManager.stopUpdatingLocation()
    }

if (gestureRecognizer.state == UIGestureRecognizerState.ended) {
    print("Map drag ended")
}
}

如果我拖动地图，应用程序会崩溃。我得到了这个：＆＃34;由于未捕获的异常终止应用程序＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39; - [app.ViewController didDragMap：]：无法识别的选择器发送到实例0x7fdf1fd132c0＆＃39;＆＃34; （..）＆＃34; libc ++ abi.dylib：以NSException类型的未捕获异常终止＆＃34;

Answer 1

Swift 3中的选择器语法已更改。您的手势识别器现在应如下所示：

let mapDragRecognizer = UIPanGestureRecognizer(target: self, action: #selector(didDragMap))

func didDragMap(_ gestureRecognizer: UIGestureRecognizer) {
   if (gestureRecognizer.state == UIGestureRecognizerState.began) {
       print("Map drag began")
       self.locationManager.stopUpdatingLocation()
   }
   if (gestureRecognizer.state == UIGestureRecognizerState.ended) {
       print("Map drag ended")
   }
}

请注意，didDragMap(_:)是根据新的Swift API Design Guidelines

声明的

我还会用if语句替换你的switch语句，因为一旦有两个以上的情况，编译器就能够更好地优化它，并且更清楚。即。

func didDragMap(_ gestureRecognizer: UIGestureRecognizer) {
    switch gestureRecognizer.state {
    case .began:
        print("Map drag began")
        self.locationManager.stopUpdatingLocation()

    case .ended:
        print("Map drag ended")

    default:
        break
    }
}

拖动mapview时停止更新位置

1 个答案: