How to get current location using Google maps sdk in ios - ios

Question

Hi i am beginner in Ios and in my project i am using Google SDK for getting route when user walking or driving along the road
But i am not able to get current location and showing in my x code console 0.0 and 0.0(latitude and longitude values) please help me some one for getting current location
My code is below:-
#import "ViewController.h"
#interface ViewController ()
{
GMSMapView *_mapView;
NSMutableArray *_coordinates;
LRouteController *_routeController;
GMSPolyline *_polyline;
GMSMarker *_markerStart;
GMSMarker *_markerFinish;
}
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_mapView.settings.myLocationButton = YES;
_mapView.myLocationEnabled = YES;
_mapView.delegate = self;
}
- (void)loadView{
CLLocation *myLocation = _mapView.myLocation;
GMSMarker *marker = [[GMSMarker alloc] init];
marker.position = CLLocationCoordinate2DMake(myLocation.coordinate.latitude, myLocation.coordinate.longitude);
marker.title = #"Current Location";
marker.map = _mapView;
GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:myLocation.coordinate.latitude
longitude:myLocation.coordinate.longitude
zoom:6];
_mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];
self.view = _mapView;
NSLog(#"%f, %f", myLocation.coordinate.latitude, myLocation.coordinate.longitude);
}
#pragma mark - GMSMapViewDelegate
- (void)mapView:(GMSMapView *)mapView didTapAtCoordinate:(CLLocationCoordinate2D)coordinate
{
_polyline.map = nil;
_markerStart.map = nil;
_markerFinish.map = nil;
[_coordinates addObject:[[CLLocation alloc] initWithLatitude:coordinate.latitude longitude:coordinate.longitude]];
if ([_coordinates count] > 1)
{
[_routeController getPolylineWithLocations:_coordinates travelMode:TravelModeDriving andCompletitionBlock:^(GMSPolyline *polyline, NSError *error) {
if (error)
{
NSLog(#"%#", error);
}
else if (!polyline)
{
NSLog(#"No route");
[_coordinates removeAllObjects];
}
else
{
_markerStart.position = [[_coordinates objectAtIndex:0] coordinate];
_markerStart.map = _mapView;
_markerFinish.position = [[_coordinates lastObject] coordinate];
_markerFinish.map = _mapView;
_polyline = polyline;
_polyline.strokeWidth = 3;
_polyline.strokeColor = [UIColor blueColor];
_polyline.map = _mapView;
}
}];
}
}
#end

Answer 1

getting the location is an asynchronous process. So you need to 'wait' for the location to be updated -- in this case by observing "myLocation"
observe location
this code only works if _mapView is onscreen
// Listen to the myLocation property of GMSMapView.
[_mapView addObserver:self
forKeyPath:#"myLocation"
options:NSKeyValueObservingOptionNew
context:NULL];
// Ask for My Location data after the map has already been added to the UI.
dispatch_async(dispatch_get_main_queue(), ^{
_mapView.myLocationEnabled = YES;
});
get the location updates:
- (void)observeValueForKeyPath:(NSString *)keyPath
ofObject:(id)object
change:(NSDictionary *)change
context:(void *)context {
if (!_firstLocationUpdate) {
// If the first location update has not yet been recieved, then jump to that
// location.
_firstLocationUpdate = YES;
CLLocation *location = [change objectForKey:NSKeyValueChangeNewKey];
_mapView.camera = [GMSCameraPosition cameraWithTarget:location.coordinate
zoom:14];
}
}