viewDidLoad时获取用户的经度/纬度

Question

我的目的是在加载视图时获取用户的经度/纬度，并将值存储在两个变量中以供以后计算。我不需要跟踪用户位置并对其进行更新，我只需要一次获取他/她的坐标。我的代码如下所示：

- (void)viewDidLoad {
    [super viewDidLoad];
    // locationManager update as location
    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self; 
    locationManager.desiredAccuracy = kCLLocationAccuracyBest; 
    locationManager.distanceFilter = kCLDistanceFilterNone; 
    [locationManager startUpdatingLocation];
    CLLocation *location = [locationManager location];
    // Configure the new event with information from the location
    CLLocationCoordinate2D coordinate = [location coordinate];

    float longitude=coordinate.longitude;
    float latitude=coordinate.latitude;

    NSLog(@"dLongitude : %f",longitude);
    NSLog(@"dLatitude : %f", latitude); 
}

在控制台中我不断收到这个：

dLongitude : 0.000000
dLatitude : 0.000000

你能帮帮我吗？

Answer 1

即使您需要使locationManager 开始更新位置（您已经这样做了）并实现管理器在检索位置时调用的委托方法，即使您需要获取用户的位置 - 您也无法立即从位置管理器获取位置。

如果您不想跟踪用户位置 - 只需在第一次获取位置后停止在该委托方法中更新位置（并在将来需要时存储它）。

Answer 2

只要您调用[locationManager startUpdatingLocation];，您的 viewDidLoad 方法就完成了。你需要实现

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

和

- (void) locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error

你的 locationManager 在获取位置或失败时会调用它。在这两种方法中，您都可以调用[locationManager stopUpdatingLocation]。

在 didUpdateToLocation 方法中，您应该从 viewDidLoad 中移出所有代码，以 CLLocation *location = [locationManager location]; 开头，这样您将获得正确的值。

Answer 3

这对我有用

- (void)viewDidLoad {
    [super viewDidLoad];
    // locationManager update as location
    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self; 
    locationManager.desiredAccuracy = kCLLocationAccuracyBest; 
    locationManager.distanceFilter = kCLDistanceFilterNone; 
    [locationManager startUpdatingLocation];
    [locationManager stopUpdatingLocation];
    CLLocation *location = [locationManager location];
    // Configure the new event with information from the location

    float longitude=location.coordinate.longitude;
    float latitude=location.coordinate.latitude;

    NSLog(@"dLongitude : %f", longitude);
    NSLog(@"dLatitude : %f", latitude); 
}

Answer 4

试试这个代码

-(IBAction)Button:(id)sender

{

locationManager = [[CLLocationManager alloc] init]; 

locationManager.delegate = self;

locationManager.desiredAccuracy = kCLLocationAccuracyBest;

locationManager.distanceFilter = kCLDistanceFilterNone;

[locationManager startUpdatingLocation];

CLLocation *location = [locationManager location];

// 使用来自位置的信息配置新事件

CLLocationCoordinate2D coordinate = [location coordinate];

NSString *latitude = [NSString stringWithFormat:@"%f", coordinate.latitude];

NSString *longitude = [NSString stringWithFormat:@"%f", coordinate.longitude];

NSLog(@"dLatitude : %@", latitude);

NSLog(@"dLongitude : %@",longitude);

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 40, 250, 50)];

UILabel *myLabel = [[UILabel alloc] initWithFrame:CGRectMake(50, 80, 200, 50)];

UILabel *myLabel1 = [[UILabel alloc] initWithFrame:CGRectMake(50, 120, 200, 100)];

myLabel.textColor = [UIColor blackColor];

myLabel1.textColor = [UIColor blackColor];

label.backgroundColor = [UIColor clearColor];

myLabel.backgroundColor = [UIColor clearColor];

myLabel1.backgroundColor = [UIColor clearColor];

[myLabel setText:latitude];

[myLabel1 setText:longitude];

label.text = @"Current Latitude And Longitude";

[self.view addSubview:label];

[self.view addSubview:myLabel];

[self.view addSubview:myLabel1];

}

Answer 5

如果您同时获得 Lat lang (0.00 ,0.00)

这可能是您的解决方案，

第 1 步： NSLocationAlwaysUsageDescription 或 NSLocationWhenInUseUsageDescription

在Info.plist中添加这两个key

第 2 步： 然后[locationManager startUpdatingLocation];开始更新

第 3 步： 你需要实施 两种方法

-(void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {

}

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations{



 CLLocation * currentLocation = [locations lastObject];

    NSLog(@"Updated Lat %f",currentLocation.coordinate.longitude);
    NSLog(@"Updated Lang %f",currentLocation.coordinate.latitude);



}

CLLocationManagerDelegate 在您的 ViewController 界面中。

**step 4:**

-(void)viewDidLoad
{
    [super viewDidLoad];
 geocoder = [[CLGeocoder alloc] init];
    manager.delegate = self;
    manager.desiredAccuracy = kCLLocationAccuracyBest;
    [manager requestWhenInUseAuthorization];
    [manager requestAlwaysAuthorization];
    [manager startUpdatingLocation];


}