您好我正在为ios开发一个应用程序，其中一个功能必须找到用户的当前位置。这是我的代码：
import UIKit
import MapKit
import CoreLocation
import SwiftyJSON
struct City {
let name : String
let location : CLLocation
let description :String
let imageName : String
func distanceTo(location:CLLocation) -> Int
{
let distanceMeters = location.distanceFromLocation(self.location)
let distanceKilometers = distanceMeters / 1000.00
return Int(round(100 * distanceKilometers) / 100)
}
}
class FirstViewController: UIViewController, CLLocationManagerDelegate {
@IBOutlet weak var LabelTest: UILabel!
@IBOutlet weak var Slider: UISlider!
@IBOutlet weak var LabelValueSlider: UILabel!
var MySliderCurrentValue = Double()
var manager = CLLocationManager()
var userLoc: CLLocationCoordinate2D!
{
willSet{
self.orderCitysByProximity()
self.filterCitysByProximity(Int(self.Slider.value))
self.LocateMe(manager)
}
}
var cities = [City]()
var nearbyCities = [City]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let path: String = NSBundle.mainBundle().pathForResource("cities", ofType: "json") as String!
let jsonData = NSData(contentsOfFile: path) as NSData!
//let ReadableJSON = JSON ( data:jsonData, options: NSJSONReadingOptions.MutableContainers, error: nil )
do {
let jsonObject = try NSJSONSerialization.JSONObjectWithData(jsonData!, options: NSJSONReadingOptions.MutableContainers) as! [String:AnyObject]
for city in jsonObject["cities"] as! [[String:AnyObject]] {
//let coordinates = position["Position"] as! [String:CLLocationDegrees]
let cityName = city["Name"] as! String
let latitude = city["Latitude"] as! Double
let longitude = city["Longitude"] as! Double
let description = city["Description"] as! String
let image = city["Image"] as! String
let location = CLLocation(latitude: latitude, longitude: longitude)
let city = City(name: cityName, location: location,description: description, imageName: image)
cities.append(city)
// print(cities)
}
self.orderCitysByProximity()
self.filterCitysByProximity(Int(self.Slider.value))
} catch let error as NSError {
print(error)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBAction func SliderChange(sender: UISlider) {
let MySliderCurrentValue: String = String(Int(sender.value))
LabelValueSlider.text = MySliderCurrentValue
self.filterCitysByProximity(Int(sender.value))
}
@IBAction func goToTableView()
{
if let tableViewController = self.storyboard?.instantiateViewControllerWithIdentifier("tableViewController") as? TableViewController
{
tableViewController.cities = self.nearbyCities
self.navigationController?.pushViewController(tableViewController, animated: true)
}
}
func filterCitysByProximity(kilometers:Int)
{
self.nearbyCities.removeAll()
for city in self.cities {
if(city.distanceTo(self.userLoc) <= kilometers*2)
{
self.nearbyCities.append(city)
}
}
self.LabelTest.text = "you have \(self.nearbyCities.count) cities nearby"
let OrderedArray = self.nearbyCities.sort({ $0.distanceTo(self.userLoc) < $1.distanceTo(self.userLoc) })
self.nearbyCities = OrderedArray
}
func orderCitysByProximity()
{
let OrderedArray = self.cities.sort({ $0.distanceTo(self.userLoc) < $1.distanceTo(self.userLoc) })
self.cities = OrderedArray
}
@IBAction func LocateMe(sender: AnyObject) {
manager.delegate = self
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.requestWhenInUseAuthorization()
manager.startUpdatingLocation()
}
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let userlocation: CLLocation = locations[0] as CLLocation
manager.stopUpdatingLocation()
let location = CLLocationCoordinate2D(latitude: userlocation.coordinate.latitude, longitude: userlocation.coordinate.longitude)
self.userLoc = location
}
}
在底部，您将看到func locationManager，我正在尝试查找用户的当前位置。您能告诉我如何启动此功能，以便应用程序识别我何时键入userLoc。 userLoc是用户的协调，我必须在其他函数中使用它们，例如func filterCitysByProximity，以及其他函数，您可以在代码中看到它们。
答案 0 :(得分：0)
您遇到问题的原因： -
当您在viewDidLoad()中调用 CLLocationManager 的委托时，需要一些时间来检索usersCurrent Location，但即使在usersLocation可以转发给您之前，您需要usersCurrent Location的函数也是如此。因为你在viewDidLoad()中调用它们而被触发，从而导致错误！
您的代码应如下所示： -
import UIKit
import MapKit
import CoreLocation
import SwiftyJSON
struct City {
let name : String
let location : CLLocation
let description :String
let imageName : String
func distanceTo(location:CLLocation) -> Int
{
let distanceMeters = location.distanceFromLocation(self.location)
let distanceKilometers = distanceMeters / 1000.00
return Int(round(100 * distanceKilometers) / 100)
}
}
class FirstViewController: UIViewController, CLLocationManagerDelegate {
@IBOutlet weak var LabelTest: UILabel!
@IBOutlet weak var Slider: UISlider!
@IBOutlet weak var LabelValueSlider: UILabel!
var MySliderCurrentValue = Double()
var locationManager = CLLocationManager()
var userLoc : CLLocation!
var cities = [City]()
var nearbyCities = [City]()
override func viewDidLoad() {
super.viewDidLoad()
let path: String = NSBundle.mainBundle().pathForResource("cities", ofType: "json") as String!
let jsonData = NSData(contentsOfFile: path) as NSData!
do {
let jsonObject = try NSJSONSerialization.JSONObjectWithData(jsonData!, options: NSJSONReadingOptions.MutableContainers) as! [String:AnyObject]
for city in jsonObject["cities"] as! [[String:AnyObject]] {
//let coordinates = position["Position"] as! [String:CLLocationDegrees]
let cityName = city["Name"] as! String
let latitude = city["Latitude"] as! Double
let longitude = city["Longitude"] as! Double
let description = city["Description"] as! String
let image = city["Image"] as! String
let location = CLLocation(latitude: latitude, longitude: longitude)
let city = City(name: cityName, location: location,description: description, imageName: image)
cities.append(city)
}
} catch let error as NSError {
print(error)
}
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.distanceFilter = kCLDistanceFilterNone
locationManager.requestWhenInUseAuthorization()
locationManager.startMonitoringSignificantLocationChanges()
locationManager.startUpdatingLocation()
if locationManager.respondsToSelector(#selector(locationManager.requestWhenInUseAuthorization)) {
locationManager.requestWhenInUseAuthorization()
locationManager.requestLocation()
}
else {
locationManager.startUpdatingLocation()
}
}
@IBAction func SliderChange(sender: UISlider) {
let MySliderCurrentValue: String = String(Int(sender.value))
LabelValueSlider.text = MySliderCurrentValue
if userLoc != nil{
self.filterCitysByProximity(Int(sender.value), location: userLoc)
}else{
let alertC : UIAlertController = UIAlertController(title: "Iwin", message: "UserLocation Not Updated wait a while", preferredStyle: .Alert)
let okAction : UIAlertAction = UIAlertAction(title: "oK", style: .Default, handler: { (okActn) in
print("User pressed ok")
})
alertC.addAction(okAction)
alertC.popoverPresentationController?.sourceView = view
alertC.popoverPresentationController?.sourceRect = view.frame
self.presentViewController(alertC, animated: true, completion: nil)
}
}
//Segue to .. :-
@IBAction func goToTableView()
{
if let tableViewController = self.storyboard?.instantiateViewControllerWithIdentifier("tableViewController") as? TableViewController
{
tableViewController.cities = self.nearbyCities
print(nearbyCities)
self.navigationController?.pushViewController(tableViewController, animated: true)
}
}
@IBAction func LocateMe(sender: AnyObject) {
}
//Class Functions call :-
func filterCitysByProximity(kilometers:Int, location: CLLocation)
{
self.nearbyCities.removeAll()
for city in self.cities {
if(city.distanceTo(location) <= kilometers*2)
{
self.nearbyCities.append(city)
}
}
self.LabelTest.text = "you have \(self.nearbyCities.count) cities nearby"
let OrderedArray = self.nearbyCities.sort({ $0.distanceTo(location) < $1.distanceTo(location) })
self.nearbyCities = OrderedArray
}
func orderCitysByProximity(location: CLLocation)
{
let OrderedArray = self.cities.sort({ $0.distanceTo(location) < $1.distanceTo(location) })
self.cities = OrderedArray
}
//Location Manager Functions :-
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
userLoc = locations[0] as CLLocation
locationManager.stopUpdatingLocation()
print(userLoc)
self.orderCitysByProximity(userLoc)
self.filterCitysByProximity(Int(self.Slider.value), location : userLoc)
}
func locationManager(manager: CLLocationManager, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
if status == .AuthorizedWhenInUse {
print("authorised call came . . . . ")
locationManager.startUpdatingLocation()
}
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError){
print(error.localizedDescription)
locationManager.stopUpdatingLocation()
}
}
将privacy - location usage description：Result添加到您的info.plist
此外，如果您的 didUpdateLocations 功能未被调用