iOS Swift:请求用户位置

Question

我是iOS Swift的初学者,编写iOS Swift代码并使用UIWebView加载我的网页.

我的网页将要求用户启用用户位置.

我想在iOS Swift代码中执行类似的操作(弹出一个对话框并说"TestApp想访问你的位置.你同意吗？")

我在Simulator上运行,但在使用CLLocationManager时失败了

以下是我的Swift代码

import UIKit
import CoreLocation

class ViewController: UIViewController, CLLocationManagerDelegate {
@IBOutlet weak var customWebView: UIWebView!


override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    if let url = NSURL(string: "http://ctrlq.org/maps/where/") {
        let request = NSURLRequest(URL: url)
        customWebView.loadRequest(request)

        let locationManager = CLLocationManager()
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.requestAlwaysAuthorization()
        locationManager.startUpdatingLocation()

    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

有谁知道如何申请位置？

提前致谢.

埃里克

Answer 1

请求和更新用户位置的正确方法是通过CLLocationManagerDelegate.

在您的View Controller继承时CLLocationManagerDelegate,它似乎没有实现必要的委托功能.正如@Rob所提到的,您应该将locationManager声明为类属性,而不是局部变量.

如果/当用户更改授权状态时,此委托功能允许您实现逻辑:

func locationManager(manager: CLLocationManager!, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
    if status == .AuthorizedWhenInUse {
        // authorized location status when app is in use; update current location
        locationManager.startUpdatingLocation()
        // implement additional logic if needed...
    }
    // implement logic for other status values if needed...
}

如果/当用户位置发生变化时,此委托功能允许您实现逻辑:

func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
    if let location = locations.first as? CLLocation {
        // implement logic upon location change and stop updating location until it is subsequently updated
        locationManager.stopUpdatingLocation()
    }
}

此外,locationServicesEnabled()确定用户是否启用了位置服务.

Answer 2

你在didFinishLaunchingWithOptions中显示调用做这样的事情

let status = CLLocationManager.authorizationStatus()
    if status == .NotDetermined || status == .Denied || status == .AuthorizedWhenInUse {

        // present an alert indicating location authorization required
        // and offer to take the user to Settings for the app via
        // UIApplication -openUrl: and UIApplicationOpenSettingsURLString
        dispatch_async(dispatch_get_main_queue(), {
            let alert = UIAlertController(title: "Error!", message: "GPS access is restricted. In order to use tracking, please enable GPS in the Settigs app under Privacy, Location Services.", preferredStyle: UIAlertControllerStyle.Alert)
            alert.addAction(UIAlertAction(title: "Go to Settings now", style: UIAlertActionStyle.Default, handler: { (alert: UIAlertAction!) in
                print("")
                UIApplication.sharedApplication().openURL(NSURL(string:UIApplicationOpenSettingsURLString)!)
            }))
            // self.presentViewController(alert, animated: true, completion: nil)
            self.window?.rootViewController?.presentViewController(alert, animated: true, completion: nil)
        })

        locationManager.requestAlwaysAuthorization()
        locationManager.requestWhenInUseAuthorization()
    }

Answer 3

几点想法:

1. 您已将自己定义CLLocationManager为局部变量,当它超出范围时将被释放.

   使这成为一个类属性.

2. 如果您确实需要requestAlwaysAuthorization,请不要忘记NSLocationAlwaysUsageDescription按照文档中的说明设置plist.

   (如果您不需要总是授权,但可以使用"使用中"授权,呼叫requestWhenInUseAuthorization和设置NSLocationWhenInUseUsageDescription值.)