Convert String to CLLocationCoordinate2D in swift

问题:

using Firebase as my backend, I've got a series of strings that are latitude and longitude coordinates, how can I convert them to CLLocationCoordinate2D so that I can use them for annotations? Here is the code that gets the info from Firebase every time its updated

var UpdateRef = Firebase(url:"https://ici.firebaseio.com/users")

UpdateRef.observeEventType(.ChildChanged, withBlock: { (snapshot) in
    let MomentaryLatitude = snapshot.value["latitude"] as? String
    let MomentaryLongitude = snapshot.value["longitude"] as? String
    let ID = snapshot.value["ID"] as? String

    println("\(MomentaryLatitude)")

    var Coordinates = CLLocationCoordinate2D(latitude: MomentaryLatitude as
        CLLocationDegrees, longitude: MomentaryLongitude as CLLocationDegrees)

}

The last line doesn't work, what should I use instead?

回答1:

Use the doubleValue property:

let MomentaryLatitude = (snapshot.value["latitude"] as NSString).doubleValue
let MomentaryLongitude = (snapshot.value["longitude"] as NSString).doubleValue