LocationManager操作

CLLocationManager *locationManager = [[CLLocationManager alloc] init];

locationManager.delegate = self; //You must create an object that conforms to the CLLocationManagerDelegate protocol and assign it as the location manager’s delegate.
locationManager.desiredAccuracy = kCLLocationAccuracyBest;

locationManager.distanceFilter = 1000.0f; //Setting the Distance Filter ,locationManager.distanceFilter = kCLDistanceFilterNone;

[locationManager startUpdatingLocation];

[locationManager stopUpdatingLocation];

The Location Manager Delegate: 

The location manager delegate must conform to the CLLocationManagerDelegate protocol, which defines two methods, both of which are optional. One of these methods is called by the location manager when it has determined the current location or when it detects a change in location. The other method is called when the location manager encounters an error.

 Getting Location Updates:

calls
the locationManager:didUpdateToLocation:fromLocation: method. This method takes
three parameters:
The first parameter is the location manager that called the method.
The second parameter is a CLLocation object that defines the current
location of the device.
The third parameter is a CLLocation object that defines the previous
location from the last update.
The first time this method is called, the previous location object will be nil.

Getting Latitude and Longitude Using CLLocation:

CLLocationDegrees latitude = theLocation.coordinate.latitude; //
CLLocationDegrees longitude = theLocation.coordinate.longitude;

CLLocationDistance altitude = theLocation.altitude;//how many meters above or below sea level you are:

CLLocationDistance distance = [fromLocation distanceFromLocation:toLocation];//The code will return the distance between two CLLocation objects,fromLocation and toLocation

Error Notifications:

locationManager:didFailWithError