Question

我正在iphone sdk4.0上创建一个应用程序。在那里，确实没有调用更新位置方法。我在下面给出了我的代码。请帮助。谢谢。

-(id)init
{
    [super init];

    obj=[[UIApplication sharedApplication]delegate];

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

    return self;

}

-(void)locationManager:(CLLocationManager *)manager
   didUpdateToLocation:(CLLocation *)newLocation
          fromLocation:(CLLocation *)oldLocation
{
    NSLog(@"%f",newLocation.coordinate.latitude);

    NSLog(@"%f",newLocation.coordinate.longitude);

    obj=[[UIApplication sharedApplication]delegate];

    location=[[CLLocation alloc]initWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.longitude];
    obj.lattitude1=[NSString stringWithFormat:@"%f",newLocation.coordinate.latitude];

    obj.longitude1=[NSString stringWithFormat:@"%f",newLocation.coordinate.longitude];
    //location=[[CLLocation alloc]initWithLatitude:39.9883 longitude:-75.262227];
}

Answer 1

此外，在iOS8中，你必须有两件额外的东西：

在Info.plist中添加一个密钥，并请求位置管理员授权启动。
- NSLocationWhenInUseUsageDescription
- NSLocationAlwaysUsageDescription
您需要请求相应位置方法的授权。
- [self.locationManager requestWhenInUseAuthorization]
- [self.locationManager requestAlwaysAuthorization]

代码示例：

self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
// Check for iOS 8. Without this guard the code will crash with "unknown selector" on iOS 7.
if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
    [self.locationManager requestWhenInUseAuthorization];
}
[self.locationManager startUpdatingLocation];

来源：http://nevan.net/2014/09/core-location-manager-changes-in-ios-8/

Answer 2

嗨，您的代码似乎没问题。现在这些可能是原因：

你的init上的

：尝试检查是否有locationServicesEnabled。

locationManager = [[CLLocationManager alloc] init];
if(locationManager.locationServicesEnabled == NO){
    //Your location service is not enabled, Settings>Location Services  
}

其他原因，您可能无法获取应用的位置信息。解决方案：只需从iPhone中删除您的应用程序并重新构建，现在它应该弹出对话框以允许位置。

用它来检查错误

- (void)locationManager:(CLLocationManager *)manager
       didFailWithError:(NSError *)error
{       
    NSLog(@"Error while getting core location : %@",[error localizedFailureReason]);
    if ([error code] == kCLErrorDenied) {
        //you had denied 
    }
    [manager stopUpdatingLocation];
}

否则一切似乎都好，你已经在运行ios 4.0，它可以安装在iPhone 3G及更高版本中，如果是iPhone 2g，则可能会出现此问题。

Answer 3

确保将CLLocationManager添加为属性。

@property（非原子，强）CLLocationManager * locationManager;

Answer 4

如果您在模拟器上测试它，它将无法正常工作。

这是因为该方法仅在设备更改位置时调用（并且模拟器永远不会更改位置）。

Answer 5

您的代理中的-locationManager:didFailWithError:是否会被调用？也许您在某些时候拒绝访问位置数据，现在不会收到提示，但访问被拒绝。

Answer 6

在您的位置管理员alloc和init之后，请检查是否允许位置服务。此代码来自Apple的“LocateMe”代码示例

if (locationManager.locationServicesEnabled == NO) {
    UIAlertView *servicesDisabledAlert = [[UIAlertView alloc] initWithTitle:@"Location Services Disabled" message:@"You currently have all location services for this device disabled. If you proceed, you will be asked to confirm whether location services should be reenabled." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [servicesDisabledAlert show];
    [servicesDisabledAlert release];
}

如果您正在使用模拟器进行测试，请尝试使用设备进行测试。模拟器要求打开计算机的WiFi，并且它可以定位位于其已知位置的数据库中的WiFi基站。

didUpdateLocation方法从不调用

6 个答案: