CoreLocation learning notes for iPhone development applications

IPhoneDeveloping applicationsCoreLocation locationLearning is the content to be introduced in this article. iPhone can useCoreLocationThe framework determines its physical location. Three technologies can be used to achieve this function: GPS, Wi-FiPositioningAnd cellular base station TinPositioning. But in the program, we only need to set the expected precision levelCoreLocationDecide which technology to use to better satisfy our requests.

1. Location Manager

 
 

  
  
CLLocationManager * locationManager = [[CLLocationManager alloc] init]; // create a location manager
  
  
LocationManager. delegate = self; // sets the proxy.
  
  
LocationManager. desiredAccuracy = kCLLocationAccuracyBest; // specify the required precision level.
  
  
LocationManager. distanceFilter = 1000.0f; // you can specify a distance filter.
  
  
[LocationManager startUpdatingLocation]; // start Location Manager
 
 

2. Location Manager Proxy

There are two main proxy Methods

 
 

  
  
// This method is called when the current position and position are determined to be updated
  
  
 
  
  
-(Void) locationManager :( CLLocationManager *) manager
  
  
DidUpdateToLocation :( CLLocation *) newLocation
  
  
FromLocation :( CLLocation *) oldLocation
  
  
{
  
  
NSString * latitudeString = [[NSString alloc] initWithFormat: @ "% g", newLocation. coordinate. latitude];
  
  
// LatitudeLabel. text = latitudeString;
  
  
[LatitudeString release];
  
  
NSString * longitudeString = [[NSString alloc] initWithFormat: @ "% g", newLocation. coordinate. longpolling];
  
  
// LongitudeLabel. text = longitudeString;
  
  
[LongitudeString release];
  
  
}
  
  
// This method is called when an error occurs in location query.
  
  
 
  
  
(Void) locationManager :( CLLocationManager *) manager
  
  
DidFailWithError :( NSError *) error
  
  
{
  
  
NSString * errorType = (error. code = kCLErrorDenied )?
  
  
@ "Access Denied": @ "Unknown Error ";
  
  
UIAlertView * alert = [[UIAlertView alloc]
  
  
InitWithTitle: @ "Error getting Location"
  
  
Message: errorType
  
  
Delegate: nil
  
  
CancelButtonTitle: @ "Okay"
  
  
OtherButtonTitles: nil];
  
  
[Alert show];
  
  
[Alert release];
  
  
}
 
 

Summary:IPhoneDeveloping applicationsCoreLocation locationI hope this article will be helpful to you.