Hello I am using CoreLocation to get latitude and longitude in my map application to get latitude and longitude by using following method
- (void)viewDidLoad {
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
[locationManager startUpdatingLocation];
[super viewDidLoad];
}
The _ (void)locationManager.... method is not getting call
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
int degrees = newLocation.coordinate.latitude;
double decimal = fabs(newLocation.coordinate.latitude - degrees);
int minutes = decimal * 60;
double seconds = decimal * 3600 - minutes * 60;
NSString *lat = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
degrees = newLocation.coordinate.longitude;
decimal = fabs(newLocation.coordinate.longitude - degrees);
minutes = decimal * 60;
seconds = decimal * 3600 - minutes * 60;
NSString *longt = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
}
I want to call lati & longi on Button click event to URL. But it is not working. it passes 0000.0 lati & longi to my url. Can some one tell me how to rectify this code
I don't see any obvious problem with your init of CLLocationManager. If you are not getting callbacks perhaps it doesn't yet have a location available. You should also implement the error callback and see if it is getting called instead.
I suggest you try one of the CLLocationManager examples provided by Apple and see if you can get the example to run.
I have did this to pass latitude and longitude in to web service URL on button click...
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
if((fabs(newLocation.coordinate.latitude) > 0.001) || (fabs(newLocation.coordinate.longitude) > 0.001)) {
NSLog(#"Got location %f,%f", newLocation.coordinate.latitude, newLocation.coordinate.longitude);
if (currentLocation != nil) {
[currentLocation release];
}
currentLocation = newLocation;
[currentLocation retain];
}}
and On click event code I have just pass locationmanager.location.coordinate.latitude.....
NSString *url = [NSString stringWithFormat:#"http://.....Url..../hespdirectory/phpsqlsearch_genxml.php?lat=%f&lng=%f&radius=%f",locationManager.location.coordinate.latitude,locationManager.location.coordinate.longitude,radius];
U can directly change the CLLocation to NSString
NSString *lat=[NSString stringWithFormat:#"%f", newLocation.latitude];
NSString *lon=[NSString stringWithFormat:#"%f", newLocation.longitude];
The answers don't show it directly, but you should have assigned your controller as the CLLocationManagerDelegate to recieve the callbacks correct?
Related
My app runs perfectly on the simulator and everything works fine. But now i wanted to thest it on my iPhone and i found out that the GPS funcution don't work.
Here is my code.
[super viewDidLoad];
//eigener Standort
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
eigLat = newLocation.coordinate.latitude;
eigLon = newLocation.coordinate.longitude;
eigLatString = [NSString stringWithFormat:#"%f", eigLat];
eigLonString = [NSString stringWithFormat:#"%f", eigLon];
}
And till now everything is fine. If i use NSLog i get the right coordinates.
But then i want to use my coordinates here:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
news = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:NULL];
for (x=0; x<[news count]; x++)
{
//Berechnung der Entfernung
erdradius = 6371.1;
//Koordinaten von Datenbank in String schreiben
NSString *latitude = [[news objectAtIndex:x] objectForKey:#"Latitude"];
NSString *longitude = [[news objectAtIndex:x] objectForKey:#"Longitude"];
entfernung = 0;
double lat1 = eigLat; //eigener Standort Latitude
double long1 = eigLon; //eigener Standort Longitude
double lat2 = [latitude doubleValue]; //Standort Heurigen Latitude
double long2 = [longitude doubleValue]; //Standort Heurigen Longitude
And there I get everytime 0 for lat1 and lat2. But only if I Run the App on the iPhone. On the Simulator it works fine.
Does someone know why this could be?
The problem is that you did not get yet a GPS location in real world, so
your method connectionDidFinishLoading() is called before didUpdateToLocation() was called.
Therefoe eighValue is still 0.
Check first for valid lat and longitude:
if both are 0 then you did not get a location.
I think that you must change the logic of your program code,
you have to either
1) wait till you have a location, and then start the
connection such that connectionDidFinishLoading is called after you have a GPS coordinate.
Or
2) you store the coordinate result of the network connection, and calculate when you got your first coordinate
I'm developing an app were I would like to get device current latitude and longitude for IPhone. Is it possible to obtain this information without using GPS.
Thanks
you can use CoreLocation framework
The Core Location framework has one important class CLLocationManager.
The CLLocationManager class handles sending out updates to a delegate anytime the location is changed. it uses the delegate CLLocationManagerDelegate protocol.
you can use it like
#import <CoreLocation/CoreLocation.h>
#interface ViewController : UIViewController
<CLLocationManagerDelegate>
{
CLLocationManager *locationManager;
}
set up locationManager like this in viewDidLoad
- (void)viewDidLoad {
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
[locationManager startUpdatingLocation];
}
implement the below delegate mehod for getting changed location
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSInteger degrees = newLocation.coordinate.latitude;
double decimal = fabs(newLocation.coordinate.latitude - degrees);
int minutes = decimal * 60;
double seconds = decimal * 3600 - minutes * 60;
NSString *lattitudeStr = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
lattitudeLabel.text = lattitudeStr;
degrees = newLocation.coordinate.longitude;
decimal = fabs(newLocation.coordinate.longitude - degrees);
minutes = decimal * 60;
seconds = decimal * 3600 - minutes * 60;
NSString *longitudeStr = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
longitudeLabel.text = longitudeStr;
}
You can use CLLocationManager to get current lat and long.
create an iVar of CLLocationManager and use it.
Here is the code:
- (void)viewDidLoad
{
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
NSLog(#"OldLocation %f %f", oldLocation.coordinate.latitude, oldLocation.coordinate.longitude);
NSLog(#"NewLocation %f %f", newLocation.coordinate.latitude, newLocation.coordinate.longitude);
currentLat = [NSString stringWithFormat:#"%f",newLocation.coordinate.latitude];
currentLong = [NSString stringWithFormat:#"%f",newLocation.coordinate.longitude];
}
CLLocationManager *locationManager = [[CLLocationManager alloc] init];
CLLocation* currentLocation = [locationManager location];
NSString *loc = [NSString stringWithFormat:#"%f,%f",currentLocation.coordinate.latitude, currentLocation.coordinate.longitude];
NSLog(#"location:%#", loc);
You can get current location without GPS by using CLLocationManager if the device has WiFi or cellular data service. The location will not be as accurate as you would get from GPS but you get a result faster than from GPS.
You can request a non-GPS location from CLLocationManager by setting the desiredAccuracy property to kCLLocationAccuracyKilometer.
Using Swift
import CoreLocation
Get current location
let locationManager = CLLocationManager()
locationManager.distanceFilter = kCLDistanceFilterNone
locationManager.desiredAccuracy = kCLLocationAccuracyBest
//get the most recently retrieved user location
if let currentLocation = locationManager.location {
let longitude = currentLocation.coordinate.longitude
let latitude = currentLocation.coordinate.latitude
//work with the received data
}
Note that locationManager.location is an optional and hence should be safely unwrapped.
I'm getting a crash from this routine (IBAction)curr:(id)sender.
So I could determine which button called it.
The crash occurs when i press the button which calls the above method(curr).
It has to display current user location eventually it does but it crashes immediately after showing latitude and longitude.
received data as string
{
Error = "Lat must be provided";
Success = 0;
}
It throws exception:Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary objectAtIndex:]: unrecognized selector sent to instance 0x6e20000'
Here is my code:
-(IBAction)curr:(id)sender
{
count=0;
NSLog(#"fhfg");
NSLog(#"%#",latu);
NSLog(#"%#",longs);
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
if (count==0)
{
int degrees = newLocation.coordinate.latitude;
double decimal = fabs(newLocation.coordinate.latitude - degrees);
int minutes = decimal * 60;
double seconds = decimal * 3600 - minutes * 60;
latu= [NSString stringWithFormat:#"%d° %d' %1.4f\"", degrees, minutes, seconds];
//a=latu;
NSLog(#" Current Latitude : %#",latu);
//latLabel.text = lat;
degrees = newLocation.coordinate.longitude;
decimal = fabs(newLocation.coordinate.longitude - degrees);
minutes = decimal * 60;
seconds = decimal * 3600 - minutes * 60;
longs = [NSString stringWithFormat:#"%d° %d' %1.4f\"", degrees, minutes, seconds];
NSLog(#" Current Longitude : %#",longs);
}
}
you can check your .xib file and check first responder by right click on first responder cube symbol.
IF there is any warning symbol in first responder connect outlets than that is the reason for your application crash.
I am trying to get the location updates Particularly when the application is in background. When the application enters background it should send the location updates for every n minutes
First I tried with the Foreground, it is working fine. I copied the same code to the applicationDidEnterBackground, I am unable to print the Location Updates. I don't know where I am struck please help me.
in viewDidLoad
- (void)viewDidLoad {
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
[locationManager startUpdatingLocation];
}
and
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
int degrees = newLocation.coordinate.latitude;
double decimal = fabs(newLocation.coordinate.latitude - degrees);
int minutes = decimal * 60;
double seconds = decimal * 3600 - minutes * 60;
NSString *lat = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
latLabel.text = lat;
degrees = newLocation.coordinate.longitude;
decimal = fabs(newLocation.coordinate.longitude - degrees);
minutes = decimal * 60;
seconds = decimal * 3600 - minutes * 60;
NSString *longt = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
longLabel.text = longt;
}
I tried pasting these methods in the AppDelegate. It is not working :( . Help me
You can't simply paste the code there and expect your application to run in the background. You have to register it as an app that runs in the background. See the section Implementing Long-Running Background Tasks in this article
As per discussion with comments I suggested you to create entry in plist.
UIBackgroundModes for location in plist
And this helped.
EDIT
When you log the coordinate you need to save time somewhere probably in NSUserDefaults. After that when next time you come to log you need to find difference between current time and stored in NSUserDefaults. If interval is what you want than do log the coordinate.
Hope this helps.
How to find the nearest 100 meters latitude and longitude depending upon the current location, i have created a database in SQLITE3 which consists of set of latitudes and longitudes and corresponding there location name. Depending upon the current location i want to fetch the nearest 100 meters latitude and longitude in objective C,
I am using the following code to get the Current location,
- (void)viewDidLoad {
[super viewDidLoad];
databaseName = #"searchdata.sql";
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDir = [documentPaths objectAtIndex:0];
databasePath = [documentDir stringByAppendingPathComponent:databaseName];
[self checkAndCreateDatabase];
[self readDataFromDatabase];
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
int degrees = newLocation.coordinate.latitude;
double decimal = fabs(newLocation.coordinate.latitude - degrees);
int minutes = decimal * 60;
double seconds = decimal * 3600 - minutes * 60;
NSString *lat = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
NSLog(#" Current Latitude : %#",lat);
//latLabel.text = lat;
degrees = newLocation.coordinate.longitude;
decimal = fabs(newLocation.coordinate.longitude - degrees);
minutes = decimal * 60;
seconds = decimal * 3600 - minutes * 60;
NSString *longt = [NSString stringWithFormat:#"%d° %d' %1.4f\"",
degrees, minutes, seconds];
NSLog(#" Current Longitude : %#",longt);
//longLabel.text = longt;
}
so how to fetch or how to calculate the surrounding 100 meters latitudes and longitudes and display it.
Thanks for the help I am using the following formula
-(double)kilometresBetweenPlace1:(CLLocationCoordinate2D) place1 andPlace2:(CLLocationCoordinate2D) place2 {
double dlon = convertToRadians([pLong intValue] - [longt intValue]);
double dlat = convertToRadians([pLat intValue] - [lat intValue]);
double a = ( pow(sin(dlat / 2), 2) + cos(convertToRadians([lat intValue]))) * cos(convertToRadians([pLat intValue])) * pow(sin(dlon / 2), 2);
double angle = 2 * asin(sqrt(a));
return angle * RADIO;
}
and getting the following output 8505.369547 on return, i am just confused what is the value i am getting actually.
Perhaps the CoreLocation framework can help you with this issue? It seems the following method is made with your question in mind:
- (id)initCircularRegionWithCenter:(CLLocationCoordinate2D)center radius:(CLLocationDistance)radius identifier:(NSString *)identifier
You could test if a coordinate from your database falls within a region by using the following method:
- (BOOL)containsCoordinate:(CLLocationCoordinate2D)coordinate
I guess the above ain't ideal when your database contains a lot of locations. But perhaps one can filter out a set of locations to test based on some minimum and maximum latitude / longitude values.
Edit: as requested, an example (don't forget to import the CoreLocation framework):
- (void)startTest
{
#define COORDS_COUNT 4
#define RADIUS 10000.0f
CLLocationCoordinate2D coords[COORDS_COUNT] = {
CLLocationCoordinate2DMake(52.000004, 4.100002),
CLLocationCoordinate2DMake(53.000009, 4.000003),
CLLocationCoordinate2DMake(52.000001, 4.500008),
CLLocationCoordinate2DMake(52.000002, 3.900900),
};
CLLocationCoordinate2D center = CLLocationCoordinate2DMake(52.0f, 4.0f); // Amsterdam
CLRegion *region = [[CLRegion alloc] initCircularRegionWithCenter:center radius:RADIUS identifier:#"Amsterdam"];
for (int i = 0; i < COORDS_COUNT; i++)
{
CLLocationCoordinate2D coord = coords[i];
if ([region containsCoordinate:coord])
{
NSLog(#"location %f, %f is within %.0f meters of coord %f, %f", coord.latitude, coord.longitude, RADIUS, center.latitude, center.longitude);
}
else
{
NSLog(#"location %f, %f is not within %.0f meters of coord %f, %f", coord.latitude, coord.longitude, RADIUS, center.latitude, center.longitude);
}
}
}
Edit 2: I realize it's not exactly the answer you requested, but it seems to me this is what you need. As you can imagine the nearest 100 meters latitude / longitude near any coordinate consists of an virtually unlimited amount of coordinates in a circular region. My guess is you want to find objects within your database that are nearby some coordinate and the above code should help you achieve this. You can retrieve a set of results from your database and test if they are nearby some coordinate.
Edit 3: The following code is likely exactly what you need:
CLLocation *center = [[CLLocation alloc] initWithLatitude:52.0f longitude:4.0f]; // Amsterdam
CLLocation *location1 = [[CLLocation alloc] initWithLatitude:52.000004f longitude:4.100002f];
CLLocationDistance distance = [center distanceFromLocation:location1];
NSLog(#"%f", distance);
Edit 4: with regards to your question about the custom object for your table view, use something like this:
#interface Location : NSObject
#property (nonatomic, strong) NSString *name;
#property (nonatomic, assign) CLLocationCoordinate2D coordinate;
#end
#implementation Location
#synthesize name, coordinate;
#end