位置显示一次答案

【问题标题】：Location is displayed once位置显示一次
【发布时间】：2014-12-26 13:35:54
【问题描述】：

我只是在玩 CLLocation 类。我成功完成了以下代码。当我按下按钮时，它会在 ALert msg 中显示位置。当我再次单击相同的按钮时，位置显示错误。而且我还注意到每次我必须去设置 - 隐私 - 位置服务以始终启用访问。当应用程序正确显示当前位置时，iPhone 设置中的位置访问会变为空白。我必须再次将其设置为 Always 才能运行该应用程序。我没有在 .plists 中添加任何内容。我只写了下面的代码。我的问题是将位置访问设置为始终后，它才第一次显示正确的位置

-(CLLocationCoordinate2D) getLocation{
        CLLocationCoordinate2D coordinate;


        if ([CLLocationManager locationServicesEnabled])
        {


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



        CLLocation *location = [locationManager location];
        coordinate = [location coordinate];
        }
            return coordinate;

    }


    - (void)startTimer {

       // if ([Run isEqualToString:@"can"]) {

            i++;

            NSLog(@"the i value %d", i);

            Run =@"cant";
        CLLocationCoordinate2D coordinate = [self getLocation];

        CLGeocoder *ceo = [[CLGeocoder alloc]init];
        CLLocation *loc = [[CLLocation alloc]initWithLatitude:coordinate.latitude longitude:coordinate.longitude]; //insert your coordinates

        [ceo reverseGeocodeLocation:loc
                  completionHandler:^(NSArray placemarks, NSError error)
         {
             CLPlacemark *placemark = [placemarks objectAtIndex:0];

             NSDictionary *eventLocation = [NSDictionary dictionaryWithObjectsAndKeys:placemark.name,@"NAME",placemark.subLocality,@"SUBLOCALITY" ,placemark.postalCode,@"POSTALCODE" ,nil];

           LocationDetails= [NSMutableDictionary dictionaryWithObjectsAndKeys:eventLocation,@"value", nil];


             NSString *name=placemark.name;
             NSString *subLocality=placemark.subLocality;
             NSString *postalCode=placemark.postalCode;



             NSMutableArray *listData;
             if (!listData) listData = [[NSMutableArray alloc] init];
             [listData addObject:LocationDetails];

             NSLog(@"the Location details %@", listData);

             NSString *location=[NSString stringWithFormat:@"You are now in %@ inside the sublocality of %@ and pin code is %@",name,subLocality,postalCode];


             UIAlertView *Alert=[[UIAlertView alloc]initWithTitle:@"Location Update" message:location delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

             [Alert show];


         }

         ];

      //  }

        // contains the code you posted to start the timer
    }






    - (IBAction)getLocation:(id)sender {

        [ self startTimer];

    }

【问题讨论】：

标签： objective-c iphone ios8 cllocationmanager cllocation

【解决方案1】：

不要使用getLocation 方法，而是在类初始化时执行所有CLLocationManager 初始化。在你的@interface 中设置一个属性来保存用户的当前位置：

@property (nonatomic, strong) CLLocation *currentLocation;

并像这样实现委托方法-locationManager:didUpdateLocations:：

- (void)locationManager:(CLLocationManager*)manager didUpdateLocations:(NSArray*)locations
{
    // set the current location. The most recent location is always at the end of the
    // if there are multiple locations
    _currentLocation = locations[locations.count - 1];
}

然后，而不是CLLocationCoordinate2D coordinate = [self getLocation];，获取位置：

CLLocationCoordinate2D coordinate = _currentLocation.coordinate; // I think that's the right property.

注意：确保你的类符合CLLocationManagerDelegate

【讨论】：