Ios 从NSData方法访问locationManager CLLocation didUpdateLocation数组

我试图通过self.location访问在其方法之外保存更新位置的数组，但这返回的是浮点0.000，而不是纬度。显然，我可以从它自己的方法中获得正确的值

谢谢

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
[self.locationManager startUpdatingLocation];
self.locationManager.delegate = self;
self.location = [[CLLocation alloc] init];

NSData* data = [NSData dataWithContentsOfURL:jsonURL];
       [self performSelectorOnMainThread:@selector(fetchedData:)
                              withObject:data waitUntilDone:YES];
}

 - (void)fetchedData:(NSData *)responseData {

//Parse
NSError* error;
NSDictionary* json = [NSJSONSerialization
                  JSONObjectWithData:responseData
                             options:kNilOptions
                               error:&error];

NSDictionary* coordinates = [json objectForKey:@"jon"];

NSLog(@"Retrieved JSON: %@", coordinates);
NSNumber* coorLat = [coordinates objectForKey:@"latitude"];
NSNumber* coorLon = [coordinates objectForKey:@"longitude"];
float lat = [coorLat floatValue];
float lon = [coorLon floatValue];
self.jsonLat.text = [NSString stringWithFormat:@"%f", lat];
self.jsonLon.text = [NSString stringWithFormat:@"%f", lon];




NSLog(@"%f", self.location.coordinate.latitude); // How to access NSArray *location from           locationManager Method????? // ISSUE HERE

//生成位置字典 NSDictionary*myLocation=[NSDictionary Dictionary WithObjectsSandKeys:[NSString stringWithFormat:@%f，3.0]，@纬度，[坐标objectForKey:@经度]，@经度，零]

// Serialize myLocation Dictionary
NSData* jsonData = [NSJSONSerialization dataWithJSONObject:myLocation
                                               options:NSJSONWritingPrettyPrinted error:&error];
// Print out JSON
self.jsonGenerated.numberOfLines = 0;
self.jsonGenerated.text = [[NSString alloc] initWithData:jsonData
                                            encoding:NSUTF8StringEncoding];
}
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
 self.location = locations.lastObject;
 self.coordinateLat.text = [NSString stringWithFormat:@"%f", self.location.coordinate.latitude];
 self.coordinateLon.text = [NSString stringWithFormat:@"%f",    self.location.coordinate.longitude];
 self.altitude.text = [NSString stringWithFormat:@"%f", self.location.altitude];
 self.hAccuracy.text = [NSString stringWithFormat:@"%f", self.location.horizontalAccuracy];
 self.vAccuracy.text = [NSString stringWithFormat:@"%f", self.location.verticalAccuracy];
 self.timestamp.text = [NSString stringWithFormat:@"%@", self.location.timestamp];
 self.speed.text = [NSString stringWithFormat:@"%f", self.location.speed];
 self.course.text = [NSString stringWithFormat:@"%f", self.location.course];
 }

DidUpdateLocation在您开始更新位置后不久调用，但在startUpdatingLocation返回之前不会调用

如果您检查self.location属性，您会发现它为零

您应该在didUpdateLocations中调用web服务调用，但显然，您需要确定一种策略来决定何时请求新数据。需要考虑的一些事项：

您可以使用移动筛选仅在位置发生一定程度的更改时接收更新 初始更新后，如果不需要详细的位置信息，您可以切换到重要的位置更改服务 还可以比较当前和以前的“水平精度”值，以确定此更新是否比上次更新更精确

---

另外，请注意，初始位置可能不太准确，因此您可能需要等待一些更新才能获得准确信息

您是否在等待locationManager:didUpdateLocations:调用？我会[self.locationManager startUpdatingLocation]；然后，在下面几行完成获取数据。startUpdatingLocation不同步；在第一次调用locationManager:didUpdateLocations:之前，该位置不一定可用。在这个方法中调用了didUpdateLocations:不是吗-voidlocationManager:CLLocationManager*管理器didUpdateLocations:NSArray*位置{在viewDidLoad期间使用：self.locationManager=[[CLLocationManager alloc]init]初始化该位置；DidUpdateLocation在您开始更新位置后不久调用，但在startUpdatingLocation返回之前不会调用。如果检查self.location，您会发现它为零。您应该在didUpdateLocations中调用Web服务调用。另外，请注意，初始位置可能不太准确，因此您可能需要等待在您获得准确信息之前进行一些更新