objective-c - didUpdateToLocation 调用了多个

Question

我有一个 iOS 应用程序使用用户的当前位置。我这样做:

-(void)startGeoloc{

    NSLog(@"start geoloc");

    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    locationManager.desiredAccuracy=kCLLocationAccuracyHundredMeters;
    [locationManager startUpdatingLocation];
}

#pragma mark - CLLocationManagerDelegate methods
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    [locationManager stopUpdatingLocation];
    AppDelegate *apDelegate =(AppDelegate *)[UIApplication sharedApplication].delegate;
    apDelegate.modeGeoloc = YES;
    [self callWebService:locationManager.location];

}

这个问题是我的方法 callWebService:locationManager.location 被调用了两次，我只想调用它一次。我该怎么做？谢谢你的回答

Answer 1

要确保 locationManager 只调用一次“didUpdate...”方法，请使用 BOOL 来引用是否已找到该位置。

1. 创建 bool 变量:

   @property BOOL didFindLocation;
   

2. 在 locationManager startUpdatingLocation 之前，将新的 BOOL 设置为 NO。这样您就可以随意调用新的位置更新。

   -(void) startFindingLocation {
   
       self.didFindLocation = NO; // like this
   
       locationManager = [[CLLocationManager alloc] init];
       [locationManager setDelegate:self]
       [locationManager setDesiredAccuracy:kCLLocationAccuracyHundredMeters];
       [locationManager startUpdatingLocation];
   }
   

3. 在“didUpdateLocations”中检查它。

   - (void) locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
   
       if (!self.didFindLocation) {
           self.didFindLocation = YES;
           [locationManager stopUpdatingLocation];
   
           // do the rest of your stuff
   
       }
   }
   

如果可能，请不要在代码中的任何其他位置设置 didFindLocation 以避免混淆。