I am interested in grabbing my users current Latitude and Longitude coordinates, and displaying them literally as a NSSString in a UILabel on the view.
I don't need any MKMapView or to show anything graphically, just to display the coordinates in a UILabel. Is this possible?
Could anyone provide a starting block for me?
Thanks
Ya, its possible. Just import #import <CoreLocation/CoreLocation.h> and declare the delegate <CLLocationManagerDelegate>. then you can get the values in following delegate mathod.
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{
CLLocationCoordinate2D location=newLocation.coordinate;
NSString *s = [NSString stringWithFormat:#"%f,%f",location.latitude,location.longitude];
}
There is the CoreLocation framework which does this job. You can get the user's current location by implementing this delegate.
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
Follow the steps:
Add MapKit.framework to your project
add to .h #import "CoreLocation/CoreLocation.h" and #import "MapKit/MapKit.h"
Use delegates as, #interface yourInterface : UIViewController < MKMapViewDelegate, CLLocationManagerDelegate >
Now Add following method to your .m file
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
[self setMapCenter:newLocation.coordinate];
[self._mapView selectAnnotation:[[self._mapView annotations] lastObject] animated:YES];
lblLong.text = [nsstring stringWithFormat:#"%f", newLocation.coordinate.longitude];
lblLat = [nsstring stringWithFormat:#"%f", newLocation.coordinate.latitude];
[self.locationManager stopUpdatingLocation];
}
-(void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSLog(#"ERROR");
}
Here mention CLLocationManager *locationManager;. good luck.
Related
What is the easiest way to pass a var into another function ?
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation {
NSLog(#"%#", started);
}
I tried:
Defined a global vars:
extern NSString *started;
When I set the NSString directly and passing into another function, it works well:
-(void) startTracking:(CDVInvokedUrlCommand*)command {
started = #"testing";
}
But it doesn't work:
-(void) startTracking:(CDVInvokedUrlCommand*)command {
NSString* myarg = [command.arguments objectAtIndex:0]; // http://docs.phonegap.com/en/2.5.0/guide_plugin-development_ios_index.md.html#Developing%20a%20Plugin%20on%20iOS_writing_an_ios_cordova_plugin
started = myarg;
}
(I'm a objective-C beginner, don't understand it well)
EDIT: Seems like it only crashed when I put the app into background.
Depending on wether you are using ARC, you have to retain the object. You'll probably want to use a property on your class:
in your header:
#property(strong) NSString *started;
in implementation:
-(void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation {
NSLog(#"%#", self.started);
}
-(void) startTracking:(CDVInvokedUrlCommand*)command {
self.started = #"testing";
}
-(void) startTracking:(CDVInvokedUrlCommand*)command {
NSString* myarg = [command.arguments objectAtIndex:0];
self.started = myarg;
}
Mate, seems like you want to track the date you started receiving location information.
How about doing it like this:
// Your .h file
#interface MyClass <CLLocationManagerDelegate>
{
BOOL hasStartedUpdatingLocation;
NSDate *startDate;
CLLocationManager *locationManager;
}
...
// Your .m file
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
// ---------------------------------------------------------------
// if has NOT started updating location, record start date
// otherwise, do not execute this if statement
// ---------------------------------------------------------------
if(!hasStartedUpdatingLocation)
{
hasStartedUpdatingLocation = YES;
// this if statement should only execute once
startDate = [NSDate date]; // get the current date and time
}
else
{
// do something else
}
}
My ultimate goal is that i need to send lat and logitude to web server, every time when location changes.
I am using below code for sending lat and longitude of a device to a web server after every 2 minutes but it is not giving sometimes correct latitude and longitude as location changes.
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation
*)newLocation fromLocation:(CLLocation *)oldLocation
{
NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];
NSLog(#"Location Age%#",[NSString stringWithFormat:#"%d",locationAge]);
if (locationAge > 5) return;
// test that the horizontal accuracy does not indicate an invalid measurement
if (newLocation.horizontalAccuracy < 0) return;
NSString *stringUrl;
// BOOL check = FALSE;
NSLog(#"Before condition condition");
if(bestEffortAtLocation == nil || bestEffortAtLocation.horizontalAccuracy > newLocation.horizontalAccuracy){
NSLog(#"condition");
self.bestEffortAtLocation = newLocation;
if (newLocation.horizontalAccuracy <= locmanager.desiredAccuracy) {
// we have a measurement that meets our requirements, so we can stop updating the location
// IMPORTANT!!! Minimize power usage by stopping the location manager as soon as possible.
[locmanager stopUpdatingLocation];
locmanager.delegate = nil;
}
//check = TRUE;
}
stringUrl = [NSString stringWithFormat:URLSAVELAT,stringUserId,[NSString stringWithFormat:#"%g",self.bestEffortAtLocation.coordinate.latitude],[NSString stringWithFormat:#"%g",self.bestEffortAtLocation.coordinate.longitude]];}
For location manager i am using below code
{
locmanager = [[CLLocationManager alloc] init];
[locmanager setDelegate:self];
locmanager.distanceFilter = 10.0;
//locmanager.distanceFilter = kCLDistanceFilterNone;
[locmanager setDesiredAccuracy:kCLLocationAccuracyBest];
[locmanager startUpdatingLocation];
}
Any,even small help would be appreciated, Thank u in advance
You should use the location update call backs from the API and use updateLocation method:
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
if([self.delegate conformsToProtocol:#protocol(CoreLocationControllerDelegate)]) {
[self.delegate locationUpdate:newLocation];
}
}
Then in the viewcontroller do this:
- (void)locationUpdate:(CLLocation *)location {
//DO WHATEVER YOU WANT HERE, INCLUDING SENDING TO SERVER
}
You also need to define two protocol methods, one of which is the locationUpdate:
#protocol CoreLocationControllerDelegate
#required
- (void)locationUpdate:(CLLocation *)location;
- (void)locationError:(NSError *)error;
#end
I would not recommend doing all that you do in the didUpdateLocation: method.
trying add annotation on current location when ever i want Any number of annotation at the but it work can any help me out
i try this code
- (CLLocationCoordinate2D)coordinate;
{
CLLocationCoordinate2D theCoordinate;
theCoordinate.latitude =MKUserLocation.latitude; //37.786996;// Here we have to change the with current location
theCoordinate.longitude = MKUserLocation.longitude;
return theCoordinate;
}
Make use of CLLocationManagerDelegate method
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
[map setShowsUserLocation:TRUE];
map is the object of MKMapView.
Use this delegate method
-(void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation {
if (userLocation_) {
[userLocation_ release];
}
userLocation_ = [newLocation retain];
}
Can I get the magnetic heading value on the following delegate? If so, how can I get it into a UILabel?
- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {
}
Yup:
- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {
myLabel.text = [NSString stringWithFormat:#"%f", [newHeading magneticHeading]];
}
I've defined this subclass of CLLocation
MyLocation.h
#interface MyLocation: CLLocation {
NSString *datum;
NSString *ellipsoid;
}
#property(nonatomic,retain) NSString *ellipsoid;
#property(nonatomic,retain) NSString *datum;
MyLocation.m
#synthesize datum,ellipsoid;
Now I get a CLLocation instance through the location manager delegate
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{
//self.myPosition is a MyLocation myPosition;
self.myPosition = newLocation;
[myPosition setDatum: #"WGS 84"];
[myPosition setEllipsoid: #"WGS 84"];
}
When I do the self.myPosition = newLocation, I get an UNCAUGHT EXCEPTION and it dies
I've also tried this way with same results:
self.myPosition = (MyLocation *)newLocation;
newLocation is not an instance of ur subclass so doing that assignment or casting throws an error because it's an invalid cast, u should be seting the values of ur subclass that u want fromthe cllocation object something like
self.myPosition=[[MyLocation alloc] initWithCoordinate:newLocation.coordinate]
and so on