在地图加载之前查找用户位置

Question

我正在尝试使用以下方法查找用户的位置：

CLLocationCoordinate2D _location;
CLLocation *userLoc = nil;
if(appDelegate.clLocationManager.locationServicesEnabled){
    userLoc = mapView.userLocation.location;
    _location = userLoc.coordinate;
}

问题是我尚未初始化地图，因此上述方法不起作用。有没有一种方法可以在不使用mapkit的情况下获取用户的位置？或者我应该使用不同的技术？

Answer 1

要获取用户的位置，您需要在尝试读取位置信息之前实际“启动”位置管理器。我建议您查看 Apple 的 LocateMe 示例。

LocateMe 示例代码

简而言之，获取用户的位置信息可以分两步完成：

- (void)viewDidLoad {
    [[self locationManager] startUpdatingLocation];
}

- (CLLocationManager *)locationManager { 

    if (locationManager != nil) {       
        return locationManager; 
    }

    NSLog(@"%s, Creating new Location Manager instance.", __FUNCTION__);
    locationManager = [[CLLocationManager alloc] init]; 
    locationManager.desiredAccuracy = kCLLocationAccuracyBest; 
    locationManager.distanceFilter = DISTANCE_FILTER_VALUE;
    locationManager.delegate = self; 

    return locationManager; 
}

...然后，

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation { 
    NSLog(@"%s, location manager returned a new location.", __FUNCTION__);

    // Check if location is valid (or good enough for us), 
    // and then process the location
    if ([self locationIsValid:newLocation]) {
            [self processLocation:newLocation];

            // Very important! When your done with it, stop the location manager
            [[self locationManager] sopUpdatingLocation];

            // (Maybe even) clear it
            locationManager.delegate = nil;
            [locationManager release];
            locationManager = nil;
    }
}

希望这有帮助！

Answer 2

我几乎删除了这个问题，但看到有人投了赞成票。这似乎就是答案：

CLLocationCoordinate2D _location;
CLLocation *userLoc = nil;
if(appDelegate.clLocationManager.locationServicesEnabled){
    userLoc = appDelegate.clLocationManager.location;
    _location = userLoc.coordinate;
}

appDelegate 只是对应用程序委托的引用，我的位置管理器实例位于其中。