swift - 通过从 Parse 获取数据在 MKMapKit 上显示注释

Question

所以我尝试使用用户当前位置创建注释。在将我的应用程序连接到 Parse 之前，我可以将信息保存到 NSUserDefaults 中，并且它工作得很好。现在我正在使用 Parse，我无法弄清楚如何在一个 View Controller 中调用在 Parse 中保存的坐标，以便我可以在不同的 map View Controller 中将坐标显示为注释。我当前使用的代码是

let userLoc = NSUserDefaults.StandardUserDefaults().dictionaryForKey("Location") as! [String : NSNumber]
Let userLat = userLoc["lat"]
Let userLng = userLoc["lng"]

var latitude:CLLocationDegrees = userLat as! CLLocationDegrees
var longitude:CLLocationDegrees = userLng as! CLLocationDegrees

那么我该如何修改这段代码才能显示我保存到 Parse 的坐标呢？ 谢谢

Answer 1

我认为this answer就是您要找的

代码:

        //MARK: (471) Crossing Positions
        //*******************************************************

        let myGeoPoint = PFGeoPoint(latitude: lat, longitude:lon)
        let myParseId = PFUser.currentUser().objectId //PFUser.currentUser().objectId
        var radius = 100.0

        println("****** this is my geoPoint from map view controller: \(myGeoPoint)")


        //MARK: *** let's look for other users ***

        var nearArray : [CLLocationCoordinate2D] = []

        func filterByProximity() {
            PFQuery(className: "Position")
                .whereKey("where", nearGeoPoint: myGeoPoint, withinKilometers: radius)     //(474)
                .findObjectsInBackgroundWithBlock ({
                    objects, error in
                    if let proximityArray = objects as? [PFObject] {
//                        println("****** here the proximity matches: \(proximityArray)")
                        for near in proximityArray {
//                            println("here they are \(near)")

                            let position = near["where"] as? PFGeoPoint

                            var theirLat = position?.latitude       //this is an optional
                            var theirLong = position?.longitude     //this is an optional
                            var theirLocation = CLLocationCoordinate2D(latitude: theirLat!, longitude: theirLong!)

                            nearArray.append(theirLocation)

                            if nearArray.isEmpty {
                                println("*** ERROR! anyone close by ***")
                            } else
                            {
                                for person in nearArray {

                                    let span = MKCoordinateSpanMake(2.50, 2.50)
                                    let region = MKCoordinateRegionMake(theirLocation, span)
                                    self.mapView.setRegion(region, animated: true)

                                    let theirAnotation = MKPointAnnotation()
                                    theirAnotation.setCoordinate(theirLocation)
                                    theirAnotation.title = near["who"] as String

                                    self.mapView.addAnnotation(theirAnotation)
                                }

                            }



                        }
                        println("****** in a radius of \(radius) there are \(nearArray.count) bikers ******")

                    }
                })
        }

        filterByProximity()