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
Related
I am working on this walking/running app which calculates distance in meters and records lat-long for further use. Now when I calculate distance I get incorrect distance every time. I have compared it with other running apps and they generally show different distance than my distance.
Here is the code that I am using:
#define kDesiredAccuracy 5.0f
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
self.locationManager.distanceFilter = kDesiredAccuracy;
_routes = [[NSMutableArray alloc] init];
lastKnownLocation = nil;
-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
// return if accuracy is less than 0 or is greater than desired accuracy.
if (newLocation.horizontalAccuracy < 0)
{
return;
}
if(newLocation.horizontalAccuracy > kDesiredAccuracy)
{
return;
}
NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];
CLLocationSpeed speed = [newLocation speed];
// return if stale data or user is not moving
if (locationAge > 5.0 || speed <= 0) return;
//return if first location is found
if(lastKnownLocation == nil)
{
lastKnownLocation = newLocation;
return;
}
CLLocationDistance distance = [newLocation distanceFromLocation:(self.pramDistance > 0)?lastKnownLocation:oldLocation];
if(distance > 0)
{
// save distance for future use
NSMutableDictionary *dict=[[NSMutableDictionary alloc] init];
[dict setObject:[NSString stringWithFormat:#"%g", newLocation.coordinate.latitude] forKey:#"latitude"];
[dict setObject:[NSString stringWithFormat:#"%g", newLocation.coordinate.longitude] forKey:#"longtitude"];
[dict setObject:[NSString stringWithFormat:#"%f",distance] forKey:#"distance"];
[_routes addObject:dict];
// add distance to total distance.
self.pramDistance += distance;
}
}
Once user finishes walking/running I draw rout of walk/run on map view. For this purpose I simply draw a ploy line over MKMapView using all the recorded locations.
The map view shows zig-zag line for route and distance is always incorrect. Please suggest me where I am doing wrong and what should I amend to make it work proper?
Here is the comparison (left one is other's app and right one is mine):
Try this,
Import CLLocationManagerDelegate,
CLLocation *currentLocation = self.currentLocation;
float distanceMile = [currentLocation distanceFromLocation:[[CLLocation alloc] initWithLatitude:latitude longitude:longitude]]/1609.34;
-(void)postCurrentLocationOfDevice
{
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.distanceFilter = kCLDistanceFilterNone;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[self.locationManager startUpdatingLocation];
self.locationManager.delegate = self;
}
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
self.currentLocation = [locations objectAtIndex:0];
[self.locationManager stopUpdatingLocation];
}
-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
self.currentLocation = newLocation;
[self.locationManager stopUpdatingLocation];
}
Though I didn't get much of the help here, I found some help and idea in this question: Corelocation incorrect distances
What I did to fix the problem is:
I stored recent 5 locations in an array.
Once 5 items are stored in the array, I checked for the nearest location.
After getting nearest location I calculated distance between last best location and stored new location in last best location.
P.S.: My code is messy and naming conventions are not that generic, that's why I am not posting my code here.
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 am trying to find distance from selectedAnnotation to userLocation. I added the following code in the annotation NSObject:
-(void) setDistanceFromCurrentLocation:(CLLocation *)currentLocation{
CLLocation *location2 = [[CLLocation alloc] initWithLatitude:self.latitude longitude:self.longitude];
[self setDistance:[currentLocation distanceFromLocation:location2]];
}
- (NSString *)subtitle
{
NSString *myDistance = [NSString stringWithFormat:#"%1.1f from current location", distance];
return myDistance;
}
Now in the didUpdatedidUpdateToLocation I tried using the following logic from this question: https://stackoverflow.com/a/10881683/984248
Still getting 0.0 back. What am I doing wrong?
EDIT:
So I am calculating the distance from current location correctly now. But how do I pass this on to set it as the subtitle to a pin?
Here is how I am finding distance:
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
[self setCurrentLocation:newLocation];
// if not Current Location then update the currently displayed Dealer Annotation
for (int i=0; i<self.dataArray.count; i++){
NSDictionary *dataDictionary = [self.dataArray objectAtIndex:i];
NSArray *array = [dataDictionary objectForKey:#"Locations"];
for (int i=0; i<array.count; i++){
NSMutableDictionary *dictionary = [array objectAtIndex:i];
CLLocation *pinLocation = [[CLLocation alloc] initWithLatitude:[[dictionary objectForKey:#"Latitude"] doubleValue] longitude:[[dictionary objectForKey:#"Longitude"] doubleValue]];
[?????? setDistance:[self.currentLocation distanceFromLocation:pinLocation]];
}
}
}
Here is how I am adding pins to the map:
for (int i=0; i<self.dataArray.count; i++){
NSDictionary *dataDictionary = [self.dataArray objectAtIndex:i];
NSArray *array = [dataDictionary objectForKey:#"Locations"];
for (int i=0; i<array.count; i++){
NSMutableDictionary *dictionary = [array objectAtIndex:i];
MapAnnotation *annotation = [[MapAnnotation alloc] init];
annotation.latitude = [[dictionary objectForKey:#"Latitude"] doubleValue];
annotation.longitude = [[dictionary objectForKey:#"Longitude"] doubleValue];
CLLocationCoordinate2D coord = {.latitude =
annotation.latitude, .longitude = annotation.longitude};
MKCoordinateRegion region = {coord};
annotation.title = [dictionary objectForKey:#"Name"];
annotation.subtitle = ?????;
annotation.coordinate = region.center;
//Saving the dictionary of the pin to show contact info later
annotation.sourceDictionary = dictionary;
[mapView addAnnotation:annotation];
}
}
Just wondering, is currentLocation set to self.latitude,self.longitude?
in which case you would be trying to find the distance from yourself. Try logging the latitude and longitude values of the currentLocation parameter and the self.latitude and self.longitude variables, and make sure they are different.
If they are, then try logging [currentLocation distanceFromLocation:location2] to see if it is non zero, if it is, then your setDistance method is the problem.
Other than that all I can think of is your distance variable is getting set to 0 somewhere else, or it is a variable that does not format with %1.1f so the formatter is setting it to 0.0
I am developing for jailbreak iPhones. I am reading Beginning iOS 5 book. Currently, I have used a location code from the book and changed it slightly. The change which I have made in the code is that I am writing the location in a text file. But the program crashes. Although the same program without any modification is working perfectly.
Here is the code:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = 2.0f;
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
FILE *file = fopen("/usr/locations.txt", "a");
if (!file)
{
fprintf(file, "Error opening file");
}
if (startingPoint == nil)
self.startingPoint = newLocation;
NSString *latitudeString = [NSString stringWithFormat:#"%g\u00B0",
newLocation.coordinate.latitude];
latitudeLabel.text = latitudeString;
NSNumber *latitude = [[NSNumber alloc] initWithDouble:newLocation.coordinate.latitude];
NSNumber *longitude = [[NSNumber alloc] initWithDouble:newLocation.coordinate.longitude];
NSString *longitudeString = [NSString stringWithFormat:#"%g\u00B0",
newLocation.coordinate.longitude];
longitudeLabel.text = longitudeString;
NSString *horizontalAccuracyString = [NSString stringWithFormat:#"%gm",
newLocation.horizontalAccuracy];
horizontalAccuracyLabel.text = horizontalAccuracyString;
NSString *altitudeString = [NSString stringWithFormat:#"%gm",
newLocation.altitude];
altitudeLabel.text = altitudeString;
NSString *verticalAccuracyString = [NSString stringWithFormat:#"%gm",
newLocation.verticalAccuracy];
verticalAccuracyLabel.text = verticalAccuracyString;
CLLocationDistance distance = [newLocation
distanceFromLocation:startingPoint];
NSString *distanceString = [NSString stringWithFormat:#"%gm", distance];
distanceTraveledLabel.text = distanceString;
struct tm *local;
time_t t;
t = time(NULL);
local = localtime(&t);
fprintf(file, "Local time and Date: %s ", asctime(local));
//----------------- ------------------------------------------------------------
fprintf(file, "Latitude = %lf, Longitude = %lf \n",
newLocation.coordinate.latitude, newLocation.coordinate.longitude);
fclose(file);
}
Your most recent comment on the question says you want to print to the console instead. In order to print on the console you use NSLog(). When you use the format specifier for an object %#, the string substituted for the object is the object’s description method.
To print the location on the console use
NSLog(#"New location: %#", newLocation);
NSLog(#"Old location: %#", oldLocation);
The description method on CLLocation returns “A string of the form ‘latitude, longitude +/- accuracy m (speed kph / heading) # date-time’.”
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?