didUpdateLocation Method Never Called

2020-03-02 05:00发布

I am making one app on iphone sdk4.0.In that did update location method never called. I have given my code below.Please help.Thanks in advance.

-(id)init
{
    [super init];

    obj=[[UIApplication sharedApplication]delegate];

    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    //locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
    locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
    [locationManager startUpdatingLocation];

    return self;

}

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

    NSLog(@"%f",newLocation.coordinate.longitude);

    obj=[[UIApplication sharedApplication]delegate];

    location=[[CLLocation alloc]initWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.longitude];
    obj.lattitude1=[NSString stringWithFormat:@"%f",newLocation.coordinate.latitude];

    obj.longitude1=[NSString stringWithFormat:@"%f",newLocation.coordinate.longitude];
    //location=[[CLLocation alloc]initWithLatitude:39.9883 longitude:-75.262227];
}

6条回答
够拽才男人
2楼-- · 2020-03-02 05:16

Make sure you added CLLocationManager as a property.

@property (nonatomic , strong) CLLocationManager *locationManager;

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劫难
3楼-- · 2020-03-02 05:17

After you alloc and init your location manager, check to see if location services are allowed. This code is from Apple's "LocateMe" code sample

if (locationManager.locationServicesEnabled == NO) {
    UIAlertView *servicesDisabledAlert = [[UIAlertView alloc] initWithTitle:@"Location Services Disabled" message:@"You currently have all location services for this device disabled. If you proceed, you will be asked to confirm whether location services should be reenabled." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [servicesDisabledAlert show];
    [servicesDisabledAlert release];
}

If you're testing with the simulator, try testing with a device instead. The simulator requires that the computer's WiFi is turned on, and that it can locate a WiFi base station that's in it's database of known locations.

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姐就是有狂的资本
4楼-- · 2020-03-02 05:19

Furthermore in iOS8 you must have two extra things:

  • Add a key to your Info.plist and request authorization from the location manager asking it to start.

    • NSLocationWhenInUseUsageDescription

    • NSLocationAlwaysUsageDescription

  • You need to request authorization for the corresponding location method.

    • [self.locationManager requestWhenInUseAuthorization]

    • [self.locationManager requestAlwaysAuthorization]

Code example:

self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
// Check for iOS 8. Without this guard the code will crash with "unknown selector" on iOS 7.
if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
    [self.locationManager requestWhenInUseAuthorization];
}
[self.locationManager startUpdatingLocation];

Source: http://nevan.net/2014/09/core-location-manager-changes-in-ios-8/

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欢心
5楼-- · 2020-03-02 05:22

HI, your codes seems ok. now these can be possible reasons :

on your init: try to check if there is locationServicesEnabled or not.

locationManager = [[CLLocationManager alloc] init];
if(locationManager.locationServicesEnabled == NO){
    //Your location service is not enabled, Settings>Location Services  
}

other reason, you may disallow to get location to your app. solution: simply remove your application from iPhone and re-build, now it should popup dialog to Allow location.

use this to check error

- (void)locationManager:(CLLocationManager *)manager
       didFailWithError:(NSError *)error
{       
    NSLog(@"Error while getting core location : %@",[error localizedFailureReason]);
    if ([error code] == kCLErrorDenied) {
        //you had denied 
    }
    [manager stopUpdatingLocation];
}

otherwise all seems ok, you were already running ios 4.0 , which can be install in iPhone 3G and later, if it was iPhone 2g, then this problem may occur.

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甜甜的少女心
6楼-- · 2020-03-02 05:26

Does -locationManager:didFailWithError: in your delegate ever get called? Maybe you denied access to location data at some point and now don't get prompted, but access is denied.

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smile是对你的礼貌
7楼-- · 2020-03-02 05:32

If you are testing this on the simulator it will not work.

This happens because that method is only called when the device changes location (and the simulator never changes location).

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