我有多个需要获取用户位置的视图控制器，所以我想创建一个单独的类，ViewController 可以调用该类来获取用户的最新位置。
locationManager:didUpdateToLocation:fromLocation 返回 void。一旦计算出用户的纬度和经度，如何将纬度和经度数据传回我的 ViewControllers？
我可以尝试在我的 locationManaging 类中编写 getter 和 setter，但如果这样做，我怎么知道何时从我的 ViewController 类中调用纬度 getter 和经度 getter 方法？如何让 ViewController 的主线程等待来自 locationManaging 类的纬度和经度值？
谢谢！
正如 user1071136 所说，单例位置管理器可能是您想要的。创建一个类，NSObject 的子类，只有一个属性 a CLLocationManager。
LocationManagerSingleton.h：
#import <MapKit/MapKit.h>
@interface LocationManagerSingleton : NSObject <CLLocationManagerDelegate>
@property (nonatomic, strong) CLLocationManager* locationManager;
+ (LocationManagerSingleton*)sharedSingleton;
@end
LocationManagerSingleton.m:
#import "LocationManagerSingleton.h"
@implementation LocationManagerSingleton
@synthesize locationManager;
- (id)init {
self = [super init];
if(self) {
self.locationManager = [CLLocationManager new];
[self.locationManager setDelegate:self];
[self.locationManager setDistanceFilter:kCLDistanceFilterNone];
[self.locationManager setHeadingFilter:kCLHeadingFilterNone];
[self.locationManager startUpdatingLocation];
//do any more customization to your location manager
}
return self;
}
+ (LocationManagerSingleton*)sharedSingleton {
static LocationManagerSingleton* sharedSingleton;
if(!sharedSingleton) {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedSingleton = [LocationManagerSingleton new];
}
}
return sharedSingleton;
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
//handle your location updates here
}
- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {
//handle your heading updates here- I would suggest only handling the nth update, because they
//come in fast and furious and it takes a lot of processing power to handle all of them
}
@end
要获取最近收到的位置，只需使用[LocationManagerSingleton sharedSingleton].locationManager.location. 预热 GPS 可能需要几秒钟才能获得准确的位置。
创建一个具有latitude和longitude属性的单例类，startLocating以及endLocating。在类中，创建一个CLLocationManager实例，并将其委托设置为单例。在startLocatingand中，调用实例endLocating的相应方法。CLLocationManager使委托方法更新latitude和longitude属性。在其他ViewControllers方面，请阅读此单例latitude和longitude属性。
要知道何时从另一个读取这些属性ViewController，请在这些属性上设置观察者（请参阅NSKeyValueObserving 协议参考
在执行此操作之前，请在 Internet 上查找现有代码。
完成此操作后，使用许可许可证将其上传到 GitHub。
基于上述答案，这就是我所做的，您可以在 github https://github.com/irfanlone/CLLocationManager-Singleton-Swift上找到完整的示例
只需将此文件导入您的项目，然后您可以选择实现 LocationUpdateProtocol 或收听位置更新通知
import MapKit
protocol LocationUpdateProtocol {
func locationDidUpdateToLocation(location : CLLocation)
}
/// Notification on update of location. UserInfo contains CLLocation for key "location"
let kLocationDidChangeNotification = "LocationDidChangeNotification"
class UserLocationManager: NSObject, CLLocationManagerDelegate {
static let SharedManager = UserLocationManager()
private var locationManager = CLLocationManager()
var currentLocation : CLLocation?
var delegate : LocationUpdateProtocol!
private override init () {
super.init()
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.distanceFilter = kCLLocationAccuracyHundredMeters
locationManager.requestAlwaysAuthorization()
self.locationManager.startUpdatingLocation()
}
// MARK: - CLLocationManagerDelegate
func locationManager(manager: CLLocationManager, didUpdateToLocation newLocation: CLLocation, fromLocation oldLocation: CLLocation) {
currentLocation = newLocation
let userInfo : NSDictionary = ["location" : currentLocation!]
dispatch_async(dispatch_get_main_queue()) { () -> Void in
self.delegate.locationDidUpdateToLocation(self.currentLocation!)
NSNotificationCenter.defaultCenter().postNotificationName(kLocationDidChangeNotification, object: self, userInfo: userInfo as [NSObject : AnyObject])
}
}
}
用法：
class ViewController: UIViewController, LocationUpdateProtocol {
var currentLocation : CLLocation!
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "locationUpdateNotification:", name: kLocationDidChangeNotification, object: nil)
let LocationMgr = UserLocationManager.SharedManager
LocationMgr.delegate = self
}
// MARK: - Notifications
func locationUpdateNotification(notification: NSNotification) {
let userinfo = notification.userInfo
self.currentLocation = userinfo!["location"] as! CLLocation
print("Latitude : \(self.currentLocation.coordinate.latitude)")
print("Longitude : \(self.currentLocation.coordinate.longitude)")
}
// MARK: - LocationUpdateProtocol
func locationDidUpdateToLocation(location: CLLocation) {
currentLocation = location
print("Latitude : \(self.currentLocation.coordinate.latitude)")
print("Longitude : \(self.currentLocation.coordinate.longitude)")
}
}
这是我在 swift 中实现位置管理器单例时所做的。它基于 user1071136 的策略，以及这种 swift 模式。
//
// UserLocationManager.swift
//
// Use: call SharedUserLocation.currentLocation2d from any class
import MapKit
class UserLocation: NSObject, CLLocationManagerDelegate {
var locationManager = CLLocationManager()
// You can access the lat and long by calling:
// currentLocation2d.latitude, etc
var currentLocation2d:CLLocationCoordinate2D?
class var manager: UserLocation {
return SharedUserLocation
}
init () {
super.init()
if self.locationManager.respondsToSelector(Selector("requestAlwaysAuthorization")) {
self.locationManager.requestWhenInUseAuthorization()
}
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.distanceFilter = 50
self.locationManager.startUpdatingLocation()
}
func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
self.currentLocation2d = manager.location.coordinate
}
}
let SharedUserLocation = UserLocation()
在学习单例类获取用户位置的过程中，我下载了这段代码https://github.com/irfanlone/CLLocationManager-Singleton-Swift。在使用它在 Xcode8.3.3 Swift 3 上运行后，我无法在调试控制台中获得任何输出。事实上，我什至无法显示这个位置授权 dlalog。我怀疑来自单例的数据没有传递给视图控制器，但是我无法解决这个问题，你能看出什么问题吗？谢谢。
Swift 3 的更正代码是：
//The singleton:
import MapKit
protocol LocationUpdateProtocol {
func locationDidUpdateToLocation(_ location : CLLocation)
}
let kLocationDidChangeNotification = "LocationDidChangeNotification"
class UserLocationManager: NSObject, CLLocationManagerDelegate {
static let SharedManager = UserLocationManager()
fileprivate var locationManager = CLLocationManager()
var currentLocation : CLLocation?
var delegate : LocationUpdateProtocol!
fileprivate override init () {
super.init()
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.distanceFilter = kCLLocationAccuracyHundredMeters
locationManager.requestAlwaysAuthorization()
self.locationManager.startUpdatingLocation()
}
// MARK: - CLLocationManagerDelegate
func locationManager(manager: CLLocationManager,didUpdateToLocation newLocation: CLLocation, fromLocation oldLocation: CLLocation) {
currentLocation = newLocation
let userInfo : NSDictionary = ["location" : currentLocation!]
DispatchQueue.main.async() { () -> Void in
self.delegate.locationDidUpdateToLocation(self.currentLocation!)
NotificationCenter.default.post(name: Notification.Name(kLocationDidChangeNotification), object: self, userInfo: userInfo as [NSObject : AnyObject])
}
}
}
// The ViewController
import UIKit
import CoreLocation
class ViewController: UIViewController, LocationUpdateProtocol {
var currentLocation : CLLocation!
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.locationUpdateNotification(_:)), name: NSNotification.Name(rawValue: kLocationDidChangeNotification), object: nil)
let LocationMgr = UserLocationManager.SharedManager
LocationMgr.delegate = self
}
// MARK: - Notifications
func locationUpdateNotification(_ notification: Notification) {
let userinfo = notification.userInfo
self.currentLocation = userinfo!["location"] as! CLLocation
print("Latitude : \(self.currentLocation.coordinate.latitude)")
print("Longitude : \(self.currentLocation.coordinate.longitude)")
}
// MARK: - LocationUpdateProtocol
func locationDidUpdateToLocation(_ location: CLLocation) {
currentLocation = location
print("Latitude : \(self.currentLocation.coordinate.latitude)")
print("Longitude : \(self.currentLocation.coordinate.longitude)")
}
}