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how to get the current location position in map on iphone
(2 answers)
Closed 9 years ago.
I can't get current location. When I launch my app in different place, App can get last location. But I don't want to last location. If you close the app and restart it, now app can get current location. How can I get current location even if it is first launch of application?
- (void)viewDidLoad
{
[super viewDidLoad];
[locationManager startUpdatingLocation];
self.mapView.delegate = self;
[self.mapView setShowsUserLocation:YES];
locationManager.delegate=self;
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate=self;
locationManager.desiredAccuracy=kCLLocationAccuracyBest;
locationManager.distanceFilter=kCLDistanceFilterNone;
location = [locationManager location];
CLLocationCoordinate2D coord;
coord.longitude = location.coordinate.longitude;
coord.latitude = location.coordinate.latitude;
lat = coord.latitude;
longt = coord.longitude;
}
You are doing [locationManager startUpdatingLocation]; before setting its delegate
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate=self;
locationManager.desiredAccuracy=kCLLocationAccuracyBest;
locationManager.distanceFilter=kCLDistanceFilterNone;
[locationManager startUpdatingLocation];
And implement its delegate method
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
}
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
}
You should read the documentation provided in the Location Awareness Programming Guide.
Specifically, when you ask for the current location, the system returns the last known location right away so you can do something useful with it. If you don't care about past locations, you can discard it and only use more recent location information by looking at the timestamp property of the CLLocation returned to determine how recent it is.
You should really read the CLLocationManager documentation.
Wat you are doing will not work, since it will take some time determine the device location.
Therefor you will need to wait until the CLLocationManager notifies you that a location has been determent.
You will need to implement the CLLocationManagerDelegate which will tell you if a location is determent or if the location determination failed.
Also you should also check if location can be determent with:
if ([CCLocationManager locationServicesEnabled]) {
// The location services are available.
}
You should also check wether you are authorize to use the location services with [CCLocationManager authorizationStatus].
Related
i cant seem to get any of the didenterregion/didexitregion delegates firing , been stuck for 2 days on it
im using xcode4.2 with ios5 sdk and location simulation,
has anyone any luck getting this to work? is a 100m radius too small?(ive tried 1000 doesnt work too) or is there something wrong with my code
checked also with normal location updating and user location indeed enters region. could not find an answer anywhere as well
MainViewController(also CLLocationManagerDelegate)'s ViewDidLoad method:
mapView = [[MKMapView alloc] initWithFrame:self.view.bounds];
mapView.showsUserLocation = YES;
mapView.mapType = MKMapTypeStandard;
mapView.delegate = self;
[self.view addSubview:mapView];
MKCoordinateRegion region;// = {{0.0,0.0},{0.0,0.0}};
MKCoordinateSpan span;
span.latitudeDelta = 0.02;
span.longitudeDelta = 0.02;
CLLocationCoordinate2D coordinates =CLLocationCoordinate2DMake(1.34537, 103.84515);
region.span = span;
region.center = coordinates;
[mapView setRegion:region animated:TRUE];
[mapView regionThatFits:region];
if (locationManager==nil){
locationManager = [[CLLocationManager alloc] init];
}
[self.locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
[self.locationManager setDistanceFilter:kCLDistanceFilterNone];
self.locationManager.delegate =self;
if ([CLLocationManager regionMonitoringAvailable]){
NSLog(#"regionMonitoring available");
CLRegion* region3 = [[CLRegion alloc] initCircularRegionWithCenter:coordinates radius:100 identifier:#"region3"];
[self.locationManager startMonitoringForRegion:region3 desiredAccuracy:1.0];
NSLog(#"region = %#",region3);
NSLog(#"loc max = %f",self.locationManager.maximumRegionMonitoringDistance);
NSLog(#"location manger monitored regions = %#",self.locationManager.monitoredRegions);
also implemented all delegate methods neccessary
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSLog(#"didfailwitherror");
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSLog(#"latitude %+.10f, longitude %+.10f\n",newLocation.coordinate.latitude,newLocation.coordinate.longitude);
}
-(void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region{
NSLog(#"didenterregion");
}
-(void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region{
NSLog(#"didexitregion");
}
- (void)locationManager:(CLLocationManager *)manager monitoringDidFailForRegion:(CLRegion *)region withError:(NSError *)error
{NSLog(#"monitoringDidFailForRegion");}
thanks for any help
How have you been testing the location? The regions are a little tricky, but once they are set up, they usually work great. What I usually do to test the region is just use the custom location in the Simulator. Use the same coordinates you are adding your region. 1000M is pretty large. I've tested with regions as small as 15-20M. If you have the right coordinates, it should be fine. Try switching back and forth from Apple HQ and your custom coordinates. You should be able to see the didEnter and didExit methods trip almost instantly if you have them logged out.
The one area you may have issues with is that the callbacks might not be getting to your method. None of my regions worked until I set up my AppDelegate as the CLLocationManagerDelegate. The app delegate finally got the updates and processed them correctly. I would try adding these callbacks there first, then work your way back to your mainviewcontroller. Hope this helps.
UPDATE
Since answering this question, I have learned a few things more about region monitoring. Regions get added with a minimum region size despite what you add for default. I was told by an Apple engineer that the minimum region size is 100M. I still feel they are very accurate, but it might help to understand why it will check you in. If you need precision better than 100M, you may need to look at other options.
I have implemented the standard method of retrieving the coordinates from the gps using - (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation.
The problem is that this function is called only on initialization and not throughout the life of the program. Is this normal?
In android you would implement a listener and you would get data instantly.
Is this not the wright way how i'm doing it? If it is, what could be the problem? (btw i've checked, i don't stopUpdatingLocation)
I have a CLLocationManager inherited class named testing and initialize it
testing* cllm = [[testing alloc] init];
cllm.delegate = self;
i later start the updating
[cllm startUpdatingLocation];
self.locationManagerDelegate = delegate;
and later is called
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
but after that it isn't called anymore. I need it to be called frequently so that i may calculate the distance to a certain point X from where i am.
Agreed with #Matt, without more code the best solution I can offer is this to tell it to update every time the device is moved with:
[self.locationManager setDistanceFiler:kCLDistanceFilterNone]
Update
I went through past projects and found the code I believe you are looking for assuming your location manager subclass is working properly
- (void)viewDidLoad {
[super viewDidLoad];
//Location
// create new location manager
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
self.locationManager.distanceFilter = kCLDistanceFilterNone;
// start location manager
[self.locationManager startUpdatingLocation];
}
-(void) distanceBetweenUserandPin {
CLLocation *currentUserLocation = [[CLLocation alloc] initWithLatitude:_currentLocation.latitude longitude:_currentLocation.longitude];
CLLocation *currentPinLocation = [[CLLocation alloc] initWithLatitude:_pinLocation.latitude longitude:_pinLocation.longitude];
CLLocationDistance distanceBetweenUserAndPinMeters = [currentUserLocation distanceFromLocation:currentPinLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{
//This successfully saves Lat, Long Data to a point location
CLLocationCoordinate2D location = CLLocationCoordinate2DMake(newLocation.coordinate.latitude, newLocation.coordinate.longitude);
NSLog(#"%f, %f", location.latitude, location.longitude);
//This assigns the value of location to the ivar _currentLocation
_currentLocation = CLLocationCoordinate2DMake(location.latitude, location.longitude);
NSLog(#"%f, %f", _currentLocation.latitude, _currentLocation.longitude);
}
First, it seems strange to me that you would use a subclass of CLLocationManager, since I'm not sure what benefit that provides you. Assuming that's not the problem, however...
From the CLLocationManager documentation:
This method returns immediately. Calling this method causes the
location manager to obtain an initial location fix (which may take
several seconds) and notify your delegate by calling its
locationManager:didUpdateToLocation:fromLocation: method. After that,
the receiver generates update events primarily when the value in the
distanceFilter property is exceeded. Updates may be delivered in other
situations though. For example, the receiver may send another
notification if the hardware gathers a more accurate location reading.
What's happening is that it is being called once for the initial position fix, but it isn't calling again because other conditions haven't changed. If a user doesn't move anywhere, then new location data won't be provided since it will be the same as last time (with a few exceptions as mentioned in the docs).
When you're testing your app, make sure that you try moving around and changing your location to produce an update. If that doesn't work, try experimenting with the desiredAccuracy and distanceFilter properties:
You start standard location services by calling the
startUpdatingLocation method. This service is most appropriate for
applications that need more fine-grained control over the delivery of
location events. Specifically, it takes into account the values in the
desiredAccuracy and distanceFilter property to determine when to
deliver new events.
Other than that, I'd guess it might have to do with how you're subclassing CLLocationManager. Providing some of that code might help.
I have a MKMapView configured like so:
mapView = [[MKMapView alloc] init];
[mapView setMapType:MKMapTypeStandard];
[mapView setShowsUserLocation:YES];
[mapView setDelegate:self];
I then initialize a CLLocationManager and call startUpdatingLocation.
I am using iSimulate to send the GPS data from my phone, to the simulator, which seems to be working since the CLLocationManager delegate method is invoked with my correct GPS coordinates. However the MKMapView never moves the blue dot away from Cupertino.
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation {
NSLog(#"Did Update Location = %f / %f", [newLocation coordinate].latitude, [newLocation coordinate].longitude);
NSLog(#"Current User Location = %f / %f", [[mapView userLocation] coordinate].latitude, [[mapView userLocation] coordinate].longitude);
}
The above method outputs the following:
>>> Did Update Location = 40.740100 / -73.989900 # Correct
>>> Current User Location = 37.331693 / -122.030457 # Cupertino... Incorrect
Even if I manually update the userLocation's coordinate using:
[[mapView userLocation] setCoordinate:[newLocation coordinate]];
The dot still just sits on Cupertino. Am I missing something?
The problem with CLLocation manger is that is caches the old location and some time it returns the old location. To get a new location just check the time stamp of the CLLocation object if it is older than the time limit then ignore this location
-(void) locationManager:(CLLocationManager*)manager
didUpdateToLocation:(CLLocation*)newLocation
fromLocation:(CLLocation*) oldLocation
{
NSDate* time = newLocation.timestamp;
NSTimeInterval timePeriod = [time timeIntervalSinceNow];
if(timePeriod < 2.0 ) { //usually it take less than 0.5 sec to get a new location but you can use any value greater than 0.5 but i recommend 1.0 or 2.0
[manager stopUpdatingLocation];
// process the location
} else {
// skip the location
}
}
The dot still just sits on Cupertino. Am I missing something?
Are you testing this on the simulator? Note that in the simulator, the location dot always remains in Cupertino. Try it on a device - maybe you don't have a bug at all!
How to get current latitude & longitude
without
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation*)newLocation fromLocation:(CLLocation *)oldLocation {
}
using this method
and if i used this function , how much distance i have to travel.... so that this method will be called by corelocation framework or can i call this function programmatic ....
The CLLocationManager is the interface you must use in order to get information about the location of the device.
You can initialise and begin getting location updates whenever you like. The CLLocationManager will notify your delegate whenever a new location is received.
locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = DISTANCE_FILTER_VALUE;
locationManager.delegate = self;
[locationManager startUpdatingLocation];
Note that when you try to get the values while using a simulator and do:
nsLog(locationManager.location.coordinate.latitude); // it will give you zero
And if you use the mapkit to get the lat and long it will give you the coordinates of apple main office (If im not mistaken).
I thought that it take so much time before it actually gets your location but when I try to run it in the actual device it prompts the allow device to get current location immediately.
How do I get the current location or GPS coordinates with the Core Location framework?
first of all you need a class implementing the protocol CLLocationManagerDelegate. So at least you need to implement the method:
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
...
}
After that create an instance of CLLocationManager, set the delegate and start updating the location:
CLLocationManager *locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self; //SET YOUR DELEGATE HERE
locationManager.desiredAccuracy = kCLLocationAccuracyBest; //SET THIS TO SPECIFY THE ACCURACY
[locationManager startUpdatingLocation];
After calling startUpdatingLocation, your implementation of locationManager: didUpdateToLocation: fromLocation gets called as soon as a location fix occurs. The parameter newLocation contains your actual location. BUT the location manager will fix a location as soon as possible, even if your specifed accuracy is not given. For this case you have to check the accuracy of the new location by your own.
cheers,
anka