In Objective C, i got old location and new locations of the user
using the following method
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
if (oldLocation == nil) return;
BOOL isStaleLocation = ([oldLocation.timestamp compare:self.startTimestamp] == NSOrderedAscending);
...
}
Now i porting the code to Swift, i cant able to get the old location from the following method
func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
self.currentLocation = manager.location
}
Is there any way to get the old location or i missed anything?
There is no longer an oldLocationso you will have to rely on the timestamp of the CLLocation returned. You can check it against the current time using timeIntervalSinceNow to know if it is new or not.
Related
My code is for a Golf player app. I need the exact user location here is my present code
- (void) update_location
{
locationManager_player = [[CLLocationManager alloc] init];
locationManager_player.delegate = self;
locationManager_player.desiredAccuracy = kCLLocationAccuracyBest;
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0) {
[locationManager_player requestWhenInUseAuthorization];
}
[locationManager_player startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
// Code to handle the current user location
}
The above delegate method is not giving the exact user location. Perhaps this gives the coordinates which are 30 to 40 yards far from user current position
Thanks in advance
Location accuracy is controlled by the desiredAccuracy property of CLLocationManager. Check what is set in your case. Default value is kCLLocationAccuracyBest. You can set it to kCLLocationAccuracyBestForNavigation but it require more power requirements.
More detail here.
I am new in location services. I have used startMonitoringSignificantLocationChanges and (void)locationManager:(CLLocationManager *)manager didUpdateToLocation: (CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation method but it is not getting called as I change location value. I want to fetch location value whenever user change its location.How should i achieve this? Please help me to resolve. Thanks in advance.
You need to implement "didUpdateLocations" delegate method . Here is sample
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
NSLog(#"locations : %#",locations.description);
CLLocation *currentLocation = [locations lastObject];
NSLog(#"current location : %f %f",currentLocation.coordinate.latitude,currentLocation.coordinate.longitude);
}
In iOS 8 you need to do two extra things to get location working:
1. add one or both of the following keys to your Info.plist file:
NSLocationWhenInUseUsageDescription
NSLocationAlwaysUsageDescription
Next you need to request authorization for the corresponding location method, WhenInUse or Background. Use one of these calls:
[self.locationManager requestWhenInUseAuthorization];
[self.locationManager requestAlwaysAuthorization];
For details refer following link. http://nevan.net/2014/09/core-location-manager-changes-in-ios-8/
Supporting both iOS 5 and 6, one should call didUpdateLocations from didUpdateToLocation.
How do you make the call and build the Locations array? Any code sample, please?
Thank you.
You don't call those routines. The system, CoreLocation specifically, calls them.
I think this exact code is displayed in the WWDC 2012 session, Staying on Track with Location Services:
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
[self locationManager:manager didUpdateLocations:#[newLocation]];
}
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
// your location handling code
}
I use this code to get the longitude and latitude.
(void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation {
NSLog(#"%f",newLocation.coordinate.latitude);
self.location = newLocation;
}
But the longitude and latitude which i got has the excursion with the actual geographical position. How to solve this problem?
You should be testing the accuracy of the CLLocation object that is returned, and making sure it meets your location accuracy criteria.
if (newLocation.horizontalAccuracy > 1000) {
// Throw away this location and wait for another one as this is over 1km away
}
Also, the locationManager:didUpdateToLocation:fromLocation: method has been deprecated in iOS6 so you should use locationManager:didUpdateLocations: if you're targetting iOS6+.
I'm in the process of writing an application that shows the user's distance from a fixed point as the user walks around (i.e. the label showing the distance from the user to the point is updated every time the user moves). I use a CLLocationManager with the code shown below:
- (void)viewDidLoad
{
locationManager=[[CLLocationManager alloc]init];
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[locationManager startUpdatingLocation];
}
-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
CLLocationDistance meters = [newLocation distanceFromLocation:fixedPoint];
self.distanceLabel.text = [[NSString alloc] initWithFormat:#"Distance: %.1f feet", meters*3.2808399];
}
The label that is supposed to show the distance from the user to the point isn't updated constantly and when it is updated, it doesn't usually show the correct distance from the user to the fixed point. I was wondering if there is a better way for me to try and do this, or do the fundamental limitations of the core location framework make this impossible. Any help will be greatly appreciated.
Are you filtering out old (cached) positions? You should also filter based on accuracy, you probably don't want low accuracy locations.
You won't get continous or periodic update, the callback only occurs when the location has changed.
Assuming the device has GPS and can see enough GPS satellites to get a good position, this works fine.
-(void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation {
NSTimeInterval age = -[newLocation.timestamp timeIntervalSinceNow];
if (age > 120) return; // ignore old (cached) updates
if (newLocation.horizontalAccuracy < 0) return; // ignore invalid udpates
...
}