Question

我在我的应用locationManager中呼叫delegate，并在各种viewDidAppear的{{1}}方法中引用了getUserLatitude和getUserLongitude函数。

我的问题是我的viewControllers方法启动太快而viewDidAppear找不到用户，appDelegate得0.000000，latitude得0.000000。有谁知道我怎么解决这个问题？谢谢！

我的appDelegate采用以下定位方法构建：

longitude

我正在使用这段代码从appDelegate获取更新的位置：

- (NSString *)getUserCoordinates
{
    NSString *userCoordinates = [NSString stringWithFormat:@"latitude: %f longitude: %f", 
    locationManager.location.coordinate.latitude, 
    locationManager.location.coordinate.longitude];
    locationManager = [[CLLocationManager alloc] init];
    locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
    locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
    [locationManager startUpdatingLocation];
    return userCoordinates;
}

- (NSString *)getUserLatitude
{
    NSString *userLatitude = [NSString stringWithFormat:@"%f", 
    locationManager.location.coordinate.latitude];
    return userLatitude;
}

- (NSString *)getUserLongitude
{
    NSString *userLongitude = [NSString stringWithFormat:@"%f", 
    locationManager.location.coordinate.longitude];
    return userLongitude;
}

Answer 1

在位置管理器更新位置后，将调用委托，可在此处使用。在位置更新后，您将在didUpdateToLocation方法中获得控件

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    NSLog(@"Success ");
}


- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
    NSLog(@"Failed %d",[error code]);

}

Answer 2

我在一个应用程序中也面临同样的问题。首先分配CLLocationManager，为其设置delegate，然后调用可以解决问题的startUpdatingLocation方法。

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

设置委托后，它会调用其委托方法＆amp;给我们lattitude＆amp; longitude当前位置为。

//delegate method
- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation
{    
    self.currentLat=newLocation.coordinate.latitude;
    self.currentLong=newLocation.coordinate.longitude;
    NSLog(@"appDelegate newLocation %f  %f",self.currentLat,self.currentLong);
}

Answer 3

我通过这样做来解决这个问题。

 - (void)locationManager:(CLLocationManager *)manager 
    didUpdateToLocation:(CLLocation *)newLocation 
           fromLocation:(CLLocation *)oldLocation 
 {


     NSLog(@"Ahsan");
     if (!oldLocation ||
        (oldLocation.coordinate.latitude != newLocation.coordinate.latitude && 
         oldLocation.coordinate.longitude != newLocation.coordinate.longitude &&
         newLocation.horizontalAccuracy <= 100.0)) 
     {
        //Your code comes here...
     }
 }

viewDidAppear在locationManager可以找到用户之前调用的方法

3 个答案: