iOS8定位

    Info.plist 增加一条 NSLocationWhenInUseUsageDescription-String-提示信息

   override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)

        self.checkLocationAuthorizationStatus()
    }

    func checkLocationAuthorizationStatus() {
        if CLLocationManager.authorizationStatus() == .AuthorizedWhenInUse {
            self.mapView.showsUserLocation = true  //使用前需要进行授权检查
        } else {
            self.locationManager.requestWhenInUseAuthorization()
        }    
    }