使地图放大到用户位置和注释（swift 2）

Question

我正在使用mapkit。我想让地图缩放以显示用户的位置和注释点，而不是仅缩放到用户的当前位置。

目前我有：

      let annotation = MKPointAnnotation() 
          annotation.coordinate = CLLocationCoordinate2DMake(mapLat, mapLon) 
          annotation.title = mapTitle 
          self.map.addAnnotation(annotation) 

    func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 
    let userLoction: CLLocation = locations[0] 
    let latitude = userLoction.coordinate.latitude 
    let longitude = userLoction.coordinate.longitude 
    let latDelta: CLLocationDegrees = 0.05 
    let lonDelta: CLLocationDegrees = 0.05 
    let span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, lonDelta) 
    let location: CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude) 
    let region: MKCoordinateRegion = MKCoordinateRegionMake(location, span) 
    self.map.setRegion(region, animated: true) 
    self.map.showsUserLocation = true 
} 

它只是将缩放到用户的位置和其被锁定的位置。当我尝试滚动时，它只是跳回到用户的位置。我究竟做错了什么？如何让用户在地图上缩放或移动，而不会跳回到当前位置？

我试图放大显示注释和用户在同一视图上的位置。即使注释很远，我也希望它缩放以显示用户和注释。

Answer 1

它只是跳回到用户的位置，因为didUpdateLocations方法被多次调用。有两种解决方案。

1）如果你使用requestLocation方法，而不是startUpdatingLocation使用requestLocation

，didUpdateLocations方法被调用一次

if #available(iOS 9.0, *) { 
    locationManager.requestLocation() 
} else { 
    // Fallback on earlier versions 
} 

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 
    let userLoction: CLLocation = locations[0] 
    let latitude = userLoction.coordinate.latitude 
    let longitude = userLoction.coordinate.longitude 
    let latDelta: CLLocationDegrees = 0.05 
    let lonDelta: CLLocationDegrees = 0.05 
    let span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, lonDelta) 
    let location: CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude) 
    let region: MKCoordinateRegion = MKCoordinateRegionMake(location, span) 
    self.map.setRegion(region, animated: true) 
    self.map.showsUserLocation = true 
} 

2）如果你用requestLocation去使用标志

var isInitialized = false 

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 
    if !isInitialized { 
     // Here is called only once 
     isInitialized = true 

     let userLoction: CLLocation = locations[0] 
     let latitude = userLoction.coordinate.latitude 
     let longitude = userLoction.coordinate.longitude 
     let latDelta: CLLocationDegrees = 0.05 
     let lonDelta: CLLocationDegrees = 0.05 
     let span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, lonDelta) 
     let location: CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude) 
     let region: MKCoordinateRegion = MKCoordinateRegionMake(location, span) 
     self.map.setRegion(region, animated: true) 
     self.map.showsUserLocation = true 
    } 
}