I am building an iOS application that display a POI in a MapView, but firstly I can display the map, and with iOS8 this is begin a problem. I read a lot question in this site, but none run on my app even if the code seems right.
I entered into myapplicationTest-info.plist the following code
<key>NSLocationAlwaysUsageDescription</key>
And the code in the file.m is this:
#import "MapViewController.h"
#define IS_OS_8_OR_LATER ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
@interface MapViewController ()
@end
@implementation MapViewController
@synthesize mapView = _mapView ;
- (void)viewDidLoad
{
[super viewDidLoad];
self.mapView.delegate = self;
self.locationManager.delegate = self;
self.locationManager = [[CLLocationManager alloc] init];
if (IS_OS_8_OR_LATER) {
//[self.locationManager requestWhenInUseAuthorization];
[self.locationManager requestAlwaysAuthorization];
}
[self.locationManager startUpdatingLocation];
self.mapView.showsUserLocation = YES;
[mapView setMapType:MKMapTypeStandard];
[mapView setZoomEnabled:YES];
[mapView setScrollEnabled:YES];
}
-(void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:YES];
self.locationManager.distanceFilter = kCLDistanceFilterNone; //Whenever we move
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[self.locationManager startUpdatingLocation];
NSLog(@"%@", [self deviceLocation]);
//View Area
MKCoordinateRegion region = { { 0.0, 0.0 }, { 0.0, 0.0 } };
region.center.latitude = self.locationManager.location.coordinate.latitude;
region.center.longitude = self.locationManager.location.coordinate.longitude;
region.span.longitudeDelta = 0.005f;
region.span.longitudeDelta = 0.005f;
[mapView setRegion:region animated:YES];
}
- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation
{
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(userLocation.coordinate, 800, 800);
[self.mapView setRegion:[self.mapView regionThatFits:region] animated:YES];
}
- (NSString *)deviceLocation {
return [NSString stringWithFormat:@"latitude: %f longitude: %f", self.locationManager.location.coordinate.latitude, self.locationManager.location.coordinate.longitude];
}
- (NSString *)deviceLat {
return [NSString stringWithFormat:@"%f", self.locationManager.location.coordinate.latitude];
}
- (NSString *)deviceLon {
return [NSString stringWithFormat:@"%f", self.locationManager.location.coordinate.longitude];
}
- (NSString *)deviceAlt {
return [NSString stringWithFormat:@"%f", self.locationManager.location.altitude];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
Where is the mistake?
Why it doesn't run?
You need to provide a value for NSLocationAlwaysUsageDescription
key which is the string that describes why your app wants to use location services -
For example -
<key>NSLocationAlwaysUsageDescription</key>
<string>FindMeDonuts will use your location to identify nearby donut shops</string>
Also, rather than checking the iOS version, it is better to check if CLLocationManager responds to the authorisation selector -
if ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
[self.locationManager requestAlwaysAuthorization];
}
finally, this won't stop your map from updating, but it doesn't make sense - you are assigning a delegate to your CLLocationManager
before you allocate and initialise it.
You should say -
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate=self;
I don't know if i understand your problem.
if your problem is about the map is not show, you need to set frame of your map.
self.mapView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
hope i could help you
The best way is to use the -locationManager:didUpdateLocations method provided by CLLocationManagerDelegate.
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
[self.locationManager stopUpdatingLocation];
// Move this line here
self.mapView.showsUserLocation = YES;
}
After calling [self.locationManager startUpdatingLocation]
in ViewDidLoad, you shouldn't set self.mapView.showsUserLocation
to YES
yet as permission to use location services is not yet approved. Use the delegate to wait/get a location update from the system before setting self.mapView.showsUserLocation
to YES
.
You also need to enable location services
if([CLLocationManager resolveClassMethod:@selector(locationServicesEnabled)]) {
[CLLocationManager locationServicesEnabled];
}
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