How can I get current location from user in iOS

∥☆過路亽.° 提交于 2019-11-26 00:27:05

问题


How can I get the current location from user in iOS?


回答1:


The answer of RedBlueThing worked quite well for me. Here is some sample code of how I did it.

Header

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>

@interface yourController : UIViewController <CLLocationManagerDelegate> {
    CLLocationManager *locationManager;
}

@end

MainFile

In the init method

locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[locationManager startUpdatingLocation];

Callback function

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    NSLog(@"OldLocation %f %f", oldLocation.coordinate.latitude, oldLocation.coordinate.longitude);
    NSLog(@"NewLocation %f %f", newLocation.coordinate.latitude, newLocation.coordinate.longitude);
}

iOS 6

In iOS 6 the delegate function was deprecated. The new delegate is

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations

Therefore to get the new position use

[locations lastObject]

iOS 8

In iOS 8 the permission should be explicitly asked before starting to update location

locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
    [self.locationManager requestWhenInUseAuthorization];

[locationManager startUpdatingLocation];

You also have to add a string for the NSLocationAlwaysUsageDescription or NSLocationWhenInUseUsageDescription keys to the app's Info.plist. Otherwise calls to startUpdatingLocation will be ignored and your delegate will not receive any callback.

And at the end when you are done reading location call stopUpdating location at suitable place.

[locationManager stopUpdatingLocation];



回答2:


In iOS 6, the

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation

is deprecated.

Use following code instead

- (void)locationManager:(CLLocationManager *)manager
     didUpdateLocations:(NSArray *)locations {
    CLLocation *location = [locations lastObject];
    NSLog(@"lat%f - lon%f", location.coordinate.latitude, location.coordinate.longitude);
}

For iOS 6~8, the above method is still necessary, but you have to handle authorization.

_locationManager = [CLLocationManager new];
_locationManager.delegate = self;
_locationManager.distanceFilter = kCLDistanceFilterNone;
_locationManager.desiredAccuracy = kCLLocationAccuracyBest;

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0 &&
    [CLLocationManager authorizationStatus] != kCLAuthorizationStatusAuthorizedWhenInUse
    //[CLLocationManager authorizationStatus] != kCLAuthorizationStatusAuthorizedAlways
   ) {
     // Will open an confirm dialog to get user's approval 
    [_locationManager requestWhenInUseAuthorization]; 
    //[_locationManager requestAlwaysAuthorization];
} else {
    [_locationManager startUpdatingLocation]; //Will update location immediately 
}

This is the delegate method which handle user's authorization

#pragma mark - CLLocationManagerDelegate
- (void)locationManager:(CLLocationManager*)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status
{
    switch (status) {
    case kCLAuthorizationStatusNotDetermined: {
        NSLog(@"User still thinking..");
    } break;
    case kCLAuthorizationStatusDenied: {
        NSLog(@"User hates you");
    } break;
    case kCLAuthorizationStatusAuthorizedWhenInUse:
    case kCLAuthorizationStatusAuthorizedAlways: {
        [_locationManager startUpdatingLocation]; //Will update location immediately
    } break;
    default:
        break;
    }
}



回答3:


You use the CoreLocation framework to access location information about your user. You will need to instantiate a CLLocationManager object and call the asynchronous startUpdatingLocation message. You will get callbacks with the user's location via the CLLocationManagerDelegate that you supply.




回答4:


Try this Simple Steps....

NOTE: Please check device location latitude & logitude if you are using simulator means. By defaults its none only.

Step 1: Import CoreLocation framework in .h File

#import <CoreLocation/CoreLocation.h>

Step 2: Add delegate CLLocationManagerDelegate

@interface yourViewController : UIViewController<CLLocationManagerDelegate>
{
    CLLocationManager *locationManager;
    CLLocation *currentLocation;
}

Step 3: Add this code in class file

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self CurrentLocationIdentifier]; // call this method
}

Step 4: Method to detect current location

//------------ Current Location Address-----
-(void)CurrentLocationIdentifier
{
    //---- For getting current gps location
    locationManager = [CLLocationManager new];
    locationManager.delegate = self;
    locationManager.distanceFilter = kCLDistanceFilterNone;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    [locationManager startUpdatingLocation];
    //------
}

Step 5: Get location using this method

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    currentLocation = [locations objectAtIndex:0];
    [locationManager stopUpdatingLocation];
    CLGeocoder *geocoder = [[CLGeocoder alloc] init] ;
    [geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemarks, NSError *error)
     {
         if (!(error))
         {
             CLPlacemark *placemark = [placemarks objectAtIndex:0];
             NSLog(@"\nCurrent Location Detected\n");
             NSLog(@"placemark %@",placemark);
             NSString *locatedAt = [[placemark.addressDictionary valueForKey:@"FormattedAddressLines"] componentsJoinedByString:@", "];
             NSString *Address = [[NSString alloc]initWithString:locatedAt];
             NSString *Area = [[NSString alloc]initWithString:placemark.locality];
             NSString *Country = [[NSString alloc]initWithString:placemark.country];
             NSString *CountryArea = [NSString stringWithFormat:@"%@, %@", Area,Country];
             NSLog(@"%@",CountryArea);
         }
         else
         {
             NSLog(@"Geocode failed with error %@", error);
             NSLog(@"\nCurrent Location Not Detected\n");
             //return;
             CountryArea = NULL;
         }
         /*---- For more results 
         placemark.region);
         placemark.country);
         placemark.locality); 
         placemark.name);
         placemark.ocean);
         placemark.postalCode);
         placemark.subLocality);
         placemark.location);
          ------*/
     }];
}



回答5:


In Swift (for iOS 8+).

Info.plist

First things first. You need to add your descriptive string in the info.plist file for the keys NSLocationWhenInUseUsageDescription or NSLocationAlwaysUsageDescription depending on what kind of service you are requesting

Code

import Foundation
import CoreLocation

class LocationManager: NSObject, CLLocationManagerDelegate {

    let manager: CLLocationManager
    var locationManagerClosures: [((userLocation: CLLocation) -> ())] = []

    override init() {
        self.manager = CLLocationManager()
        super.init()
        self.manager.delegate = self
    }

    //This is the main method for getting the users location and will pass back the usersLocation when it is available
    func getlocationForUser(userLocationClosure: ((userLocation: CLLocation) -> ())) {

        self.locationManagerClosures.append(userLocationClosure)

        //First need to check if the apple device has location services availabel. (i.e. Some iTouch's don't have this enabled)
        if CLLocationManager.locationServicesEnabled() {
            //Then check whether the user has granted you permission to get his location
            if CLLocationManager.authorizationStatus() == .NotDetermined {
                //Request permission
                //Note: you can also ask for .requestWhenInUseAuthorization
                manager.requestWhenInUseAuthorization()
            } else if CLLocationManager.authorizationStatus() == .Restricted || CLLocationManager.authorizationStatus() == .Denied {
                //... Sorry for you. You can huff and puff but you are not getting any location
            } else if CLLocationManager.authorizationStatus() == .AuthorizedWhenInUse {
                // This will trigger the locationManager:didUpdateLocation delegate method to get called when the next available location of the user is available
                manager.startUpdatingLocation()
            }
        }

    }

    //MARK: CLLocationManager Delegate methods

    @objc func locationManager(manager: CLLocationManager, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
        if status == .AuthorizedAlways || status == .AuthorizedWhenInUse {
            manager.startUpdatingLocation()
        }
    }

    func locationManager(manager: CLLocationManager, didUpdateToLocation newLocation: CLLocation, fromLocation oldLocation: CLLocation) {
        //Because multiple methods might have called getlocationForUser: method there might me multiple methods that need the users location.
        //These userLocation closures will have been stored in the locationManagerClosures array so now that we have the users location we can pass the users location into all of them and then reset the array.
        let tempClosures = self.locationManagerClosures
        for closure in tempClosures {
            closure(userLocation: newLocation)
        }
        self.locationManagerClosures = []
    }
}

Usage

self.locationManager = LocationManager()
self.locationManager.getlocationForUser { (userLocation: CLLocation) -> () in
            print(userLocation)
        }



回答6:


The Xcode Documentation has a wealth of knowledge and sample apps - check the Location Awareness Programming Guide.

The LocateMe sample project illustrates the effects of modifying the CLLocationManager's different accuracy settings




回答7:


iOS 11.x Swift 4.0 Info.plist needs these two properties

<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
<string>We're watching you</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string>Watch Out</string>

And this code ... making sure of course your a CLLocationManagerDelegate

let locationManager = CLLocationManager()

// MARK location Manager delegate code + more

func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
    switch status {
    case .notDetermined:
        print("User still thinking")
    case .denied:
        print("User hates you")
    case .authorizedWhenInUse:
            locationManager.stopUpdatingLocation()
    case .authorizedAlways:
            locationManager.startUpdatingLocation()
    case .restricted:
        print("User dislikes you")
    }

And of course this code too which you can put in viewDidLoad().

locationManager.delegate = self
locationManager.requestAlwaysAuthorization()
locationManager.distanceFilter = kCLDistanceFilterNone
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestLocation()

And these two for the requestLocation to get you going, aka save you having to get out of your seat :)

func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
    print(error)
}

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    print(locations)
}



回答8:


You can use this service I wrote to handle everything for you.

This service will request the permissions and handle dealing with the CLLocationManager so you don't have to.

Use like this:

LocationService.getCurrentLocationOnSuccess({ (latitude, longitude) -> () in
    //Do something with Latitude and Longitude

    }, onFailure: { (error) -> () in

      //See what went wrong
      print(error)
})



回答9:


For Swift 5, here's a quick short class to get the location:

class MyLocationManager: NSObject, CLLocationManagerDelegate {
    let manager: CLLocationManager

    override init() {
        manager = CLLocationManager()
        super.init()
        manager.delegate = self
        manager.distanceFilter = kCLDistanceFilterNone
        manager.desiredAccuracy = kCLLocationAccuracyBest
        manager.requestWhenInUseAuthorization()
        manager.startUpdatingLocation()
    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        // do something with locations
    }
}



来源:https://stackoverflow.com/questions/4152003/how-can-i-get-current-location-from-user-in-ios

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