I'd like to be able to get my current user's location without actually having a map view on my view controller.
At the moment I do have a map view and get the user location by calling one of the delegate methods....
- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation
{
userlatitude = userLocation.location.coordinate.latitude;
userlongitude = userLocation.location.coordinate.longitude;
}
CLLocationManager is the class that is responsible for keeping user's location values. CLLocationManagerDelegate is another class that gets real time location data from iDevice's GPS and notifies CLLocationManager instance about the change in location and various other events, via it's delegate methods. It would be very helpful if you would read the related documentation.
You must implement CLLocationManagerDelegate protocol inside your class.
You must also have CLLocationManager instance within your class that should monitor the location.
In your project, you must also add Core Location framework in Link Binaries section.
The simplest way would be:
Your .h file:
#interface MyViewController : UIViewController<CLLocationManagerDelegate>
{
CLLocation * currentLocation;
CLLocationManager * locationManager;
}
#end
Your .m file:
- (void) viewDidLoad
{
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
[locationManager startUpdatingLocation];
}
//remember to stop before you are done, either here or in view disappearance.
- (void) dealloc
{
[locationManager stopUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateLocations:(NSArray *)locations
{
currentLocation = (CLLocation *)[locations lastObject];
}
Easily, use CCLocationManager instead of the MKMapKit::userLocaiton method.
Take a look at the "LocateMe" sample project on developer.apple.com.
Related
I want to get the latitude and longitude of the user and display it on the Apple Watch.
I have already included the core location framework in my Watchkit Extension.
When I run the program all I get for the lat and long is 0.0 and 0.0
I tested the same method in a class on the iPhone and it worked, and gave me the appropriate coordinates. What am I doing wrong?
The .h file:
#import <WatchKit/WatchKit.h>
#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>
#interface InterfaceController : WKInterfaceController
#end
The .m file:
#import "InterfaceController.h"
#interface InterfaceController()
#end
#implementation InterfaceController
- (void)awakeWithContext:(id)context {
[super awakeWithContext:context];
// Configure interface objects here.
}
- (void)willActivate {
// This method is called when watch view controller is about to be visible to user
[super willActivate];
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
if ([self.locationManager respondsToSelector:#selector(requestWhenInUseAuthorization)]) {
[self.locationManager requestWhenInUseAuthorization];
}
[self.locationManager startUpdatingLocation];
}
- (void)didDeactivate {
// This method is called when watch view controller is no longer visible
[super didDeactivate];
}
- (IBAction)showLocation {
NSString * geoLoc = [NSString stringWithFormat:#"latitude: %f longitude: %f", self.locationManager.location.coordinate.latitude, self.locationManager.location.coordinate.longitude];
NSLog(geoLoc);
}
#end
Before you can get any location updates to your watch app extension you will need to authorize location updates in your iPhone app. If you haven't authorized location updates in your iPhone app, then your watch extension will not get any location updates. Also, I am pretty sure you need to set the permission to always allow for location updates [CLLocationManager requestAlwaysAuthorization]. I don't think it will work if you use [CLLocationManager requestWhenInUseAuthorization], though I am not 100% sure about the permissions.
In Xcode, you want use the Debug menu to simulate a location that's either pre-set or use a GPX file as the location source.
In the CLLocationMananager documentation, the location property states
The value of this property is nil if no location data has ever been retrieved.
That means that you need to call [self.locationManager startUpdatingLocation] in order to get a valid location. But there a could things you need to do before that will work.
First of all you will need to request authorization by calling [self.locationManager requestAlwaysAuthorization].
When authorization is approved or declined, the delegate method locationManager:didChangeAuthorizationStatus: will be called.
If the authorization status is kCLAuthorizationStatusAuthorizedAlways than you can call [self.locationManager startUpdatingLocation].
Then anytime the location is updated, the delegate method
locationManager:didUpdateLocations: will be called so you can update your UI with the new location.
You are not supposed to request location data within a WatchKit Extension.
From Apple Watch Human Interface Guidelines:
“Avoid using technologies that request user permission, like Core
Location. Using the technology from your WatchKit extension could
involve displaying an unexpected prompt on the user’s iPhone the first
time you make the request. Worse, it could happen at a time when the
iPhone is in the user’s pocket and not visible.”
I am using this code
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
[locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8)
{
[locationManager requestAlwaysAuthorization];
[locationManager requestWhenInUseAuthorization];
}
[locationManager startUpdatingLocation];
and to display in wkinterfaceMap i use this code
CLLocationCoordinate2D mapLocation = CLLocationCoordinate2DMake([latitude floatValue],[longitude floatValue]);
//
MKCoordinateSpan coordinateSpan = MKCoordinateSpanMake(1, 1);
[self.mapkit addAnnotation:mapLocation withPinColor: WKInterfaceMapPinColorPurple];
[self.mapkit setRegion:(MKCoordinateRegionMake(mapLocation, coordinateSpan))];
I'm trying to getting my current location exact according to my coordinates. I've implemented CLLocationManager in my viewController called myLocation.
My problem is, I'm getting not getting my co-ordinates for the first time, but when I again approach I got the coordinates. I'm unable to understand this problem that why this not appear for the first time.
I also tried to give a NSTimer to stoplocation but but still unable to get the result for the first time, every first time I getting a (null) value, and then getting the co-ordinates.
My Code:
#import <UIKit/UIKit.h>
#import <Corelocation/CoreLocation.h>
#interface myLocation : UITableViewController<CLLocationManagerDelegate>
#property (strong, nonatomic) CLLocationManager *locationManager;
#end
#interface myLocation () {
CLLocationManager* _locationManager;
NSString * _lat;
NSString * _lng;
}
#end
#implementation myLocation
- (void)viewDidLoad
{
[super viewDidLoad];
_locationManager = [[CLLocationManager alloc] init];
_locationManager.distanceFilter = kCLDistanceFilterNone;
_locationManager.delegate = self;
_locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
[_locationManager requestWhenInUseAuthorization];
[_locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateLocations:(NSArray *)locations {
CLLocation *location = [locations lastObject];
[_locationManager stopUpdatingLocation];
_lat =[NSString stringWithFormat:#"%f",location.coordinate.latitude];
_lng =[NSString stringWithFormat:#"%f",location.coordinate.longitude];
}
- (void)viewWillAppear:(BOOL) animated
{
NSLOG(#"%#",_lat);
NSLOG(#"%#",_lng);
}
Your coordinates aren't appearing yet when you attempt to print them in viewWillAppear: because the CLLocationManager hasn't had enough time to retrieve the first location yet. Wait until didUpdateLocations: is first called before attempting to utilize the device coordinates because didUpdateLocations: is where you'll be receiving those coordinates. I recommend deleting your attempt to print the coordinates code from your viewWillAppear and simply print them in didUpdateLocations: instead.
In the comments, the OP stated he wants to "refresh" the location during viewWillAppear. I suggest stopping the updates when the view disappears and restarting the updates as soon as the view reappears:
- (void)viewWillAppear:(BOOL) animated
{
[_locationManager startUpdatingLocation];
}
- (void)viewWillDisappear:(BOOL) animated
{
[_locationManager stopUpdatingLocation];
}
It takes some time for location services to start up and call your delegate method - This almost certainly won't happen before viewWillAppear is called if you are only starting location services in viewDidLoad. Also, the first time your app executes it has to wait for the user to grant permission.
You can examine the location property of your CLLocationManager to get the most recent location. If it is nil then no location has been determined (yet).
I have a location app that had the following method in the header of the ViewController.m file for the past couple of days:
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations;
However, I just deleted the above out of my code and the app still runs 100% fine. I don't understand how this is possible when the xcode documentation clearly says that the purpose of this method is to "tell the delegate when new location data is available."
The only thing I can think of is that it says "new location data" and that the above method is already setup in the CoreLocation.h file that I imported, and therefore already available for my use and has already stored the data.
Just want to make sure I understand the theory behind all of this before I move on.
Thank you for the help in clearing this up.
Here is my entire ViewController.m code(with the method still included):
#import "ViewController.h"
#import <CoreLocation/CoreLocation.h>
#interface ViewController () <CLLocationManagerDelegate>
//This tells the delegate that new location data is available. Manager is the object that updates the event, and the locations object is where the array of location data is stored.
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.gpsLM = [[CLLocationManager alloc]init];
NSLog(#"Location services enabled: %u",[CLLocationManager authorizationStatus]);
[self.gpsLM startUpdatingLocation];
self.gpsLM.delegate = self;
CLLocation * currentLocation = self.gpsLM.location;
NSLog(#"Your current location is: %#", currentLocation);
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
-(IBAction)gpsButton{
CLLocation * currentLocation = self.gpsLM.location;
self.gpsLabel.text = [NSString stringWithFormat:#"Your Location is %#", currentLocation];
NSLog(#"Location services enabled: %u",[CLLocationManager authorizationStatus]);
NSLog(#"Your current location is: %#", currentLocation);
}
#end
iOS checks if your class is capable of receiving the data with something like:
if ( [delegate respondsToSelector:#selector(didUpdateLocations:)] ){
[delegate performSelector:#selector(didUpdateLocations:) withArgs:....]
}
So if your delegate doesn't implement the method, then it doesn't attempt to send it.
I am using CLLocationManager class. I have a simple class method for capturing the location
+(void)captureLocation{
mLocationManager = [[CLLocationManager alloc]init];
mLocationManager.delegate = (id<CLLocationManagerDelegate>)self;
mLocationManager.desiredAccuracy = kCLLocationAccuracyBest;
[mLocationManager startUpdatingLocation];
}
and i have the delegate methods of CLLocationManager also
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
}
now i am trying to call this method in my viewDidLoad as
- (void)viewDidLoad
{
[super viewDidLoad];
[myclass captureLocation];
}
the method is getting called but the delegate methods are not getting called.
I have other class method also and from there if I try to call the method again the captureLocation method is getting called but the delegate methods are not called. Here is the other class method
+(void)initialize{
[self captureLocation];
}
please help me to find out why delegate methods are not getting called as I am new to this field. Thanks in advance.
Also know that CoreLocation permissions have changed with iOS 8. If you don't request the new permissions authorizations, CoreLocation doesn't do anything. It fails quietly because the delegate methods are never called.
I realize this question was asked in 2013, but if you are having a similar problem with the delegate methods not getting called, this article is extremely helpful:
http://nevan.net/2014/09/core-location-manager-changes-in-ios-8/
While the article is very detailed and long, the actual code fix can be as minor as this:
if ([locationManager respondsToSelector:#selector(requestWhenInUseAuthorization)]) {
[locationManager requestWhenInUseAuthorization];
}
And you have to add a value to info.plist, which is the message to display in the permissions alert. See screen grab.
Key: NSLocationWhenInUseUsageDescription
Value: Location is required to find out where you are (You can change that to whatever you want)
You are setting the delegate of the CLLocationManager inside a class method (i.e. one prefixed by + rather than -). So, when you reference self within that class method, that's the class, not an instance of the class. So, you are trying to set the delegate to the class rather than an instance of the class.
That won't work. The delegate methods are instance methods, not class methods. (This is presumably why you had to use the CLLocationManagerDelegate cast when assigning the delegate.)
You must actually instantiate whichever class you've implemented the CLLocationManagerDelegate methods. If you don't want to tie that instance to a particular view controller, you could use a singleton pattern. Regardless, you can set the location manager's delegate to point to that instance of that class.
For example, if you wanted it to be a singleton:
// MyClass.h
#import <Foundation/Foundation.h>
#interface MyClass : NSObject
+ (instancetype)sharedManager;
- (void)startCapture;
- (void)stopCapture;
#end
and
// MyClass.m
#import "MyClass.h"
#import <CoreLocation/CoreLocation.h>
#interface MyClass () <CLLocationManagerDelegate>
#property (nonatomic, strong) CLLocationManager *locationManager;
#end
#implementation MyClass
+ (instancetype)sharedManager
{
static id sharedMyManager = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedMyManager = [[self alloc] init];
});
return sharedMyManager;
}
- (void)startCapture
{
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[self.locationManager startUpdatingLocation];
}
- (void)stopCapture
{
[self.locationManager stopUpdatingLocation];
self.locationManager = nil;
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
// ...
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
// ...
}
#end
And then,
- (void)viewDidLoad
{
[super viewDidLoad];
[[MyClass sharedInstance] startCapture];
}
Calling self in a + method set your delegate to nil as it means ClassName as in [[ClassName alloc] init].
you need to:
mLocationManager.delegate = mLocationManager
instead of
mLocationManager.delegate (id<CLLocationManagerDelegate>)self;
in ios6 locationManager:didUpdateToLocation:fromLocation: is deprecated so you need to add another method in your code ...
-(void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
// this method get called in ios7 .
}
In iOS -8 need to do some changes :
Please have a look into this :Get current location in iOS-7 and iOS-8
I'm getting an error in my IOS application. I've searched in the google and here, but the specific solution was not found!
I have a viewController called mapView that I use in two moments in my app, this view contains a MKMapView and the code.
In my mapView.h there is:
#property (strong, nonatomic) IBOutlet MKMapView *mapSpot;
And in my mapView.m there is:
- (void)viewDidLoad {
[super viewDidLoad];
[mapSpot setShowsUserLocation:YES];
}
- (void) mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation{
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance([userLocation coordinate], 500, 500);
[mapSpot setRegion:region animated:YES];
}
So, in the first moment I load the mapView into other ViewController using:
#property (strong, nonatomic) ViewMap *mapView;
mapView = [[ViewMap alloc] initWithNibName:#"ViewMap" bundle:nil];
[self.view addSubview:[mapView view]];
I unload that ViewController and in another ViewController in other moment I load the MapView again, but in this moment the method: - (void) mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation not is called.
I verify if the first ViewController was unloaded and that was.
When I load the second ViewController there is a new instace of MapView, but not call the delegate method.
Anyone know something about that?
Thanks
==================================================================================
EDIT AND SOLVED:
the problem is in the way you are adding the view, in this line
[self.view addSubview:[mapView view]];
if you only add the view the controller code is not executed, instead of that you has to present the mapView, for example:
[self presentViewController:mapView animated:YES completion:nil];
The problem above, maybe happen because I'm using simulator to test app, and how the simulator not change the position map not get didUpdateUserLocation:
That's the unique explanation that I could have after the review the code, organize the classes read documentation and get error again.
Now, I'm using CLLocationManager to get position, after getting first time the position I stop it.
In the future I'll implement a system that track the user path, so using CLLocationManager is inevitable.
The mapView.m code after changes:
- (void)viewDidLoad {
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations{
CLLocation *loc = [locations lastObject];
// store the location to use in any moment, it needs to be checked because the first time when get the coordinate not pass infos to load places according the current position
if (!location.latitude) {
location = [loc coordinate];
// set center the map at the current position
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(location, 500, 500);
[mapSpotView setRegion:region animated:YES];
[[NSNotificationCenter defaultCenter] postNotificationName:#"loadPlaces" object:nil];
[locationManager stopUpdatingLocation];
}
}
if someone has a better solution, please, post here!
That's it!