I am new to objective c. My program is when start button is pressed, the location coordinates should start tracking and the distance should get tracked simultaneously and when stop button is pressed, the the tracking should stop and the distance should be displayed.
The CLLocationManagerDelegate helps to achieve this when you set the delegate to self after you have confirmed to it.
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
this method is called each time when your location is changed as a callback function.
Here is a small tutorial that might give you a step by step instruction: http://www.mobisoftinfotech.com/blog/iphone/1474/
I hope it helps you. Cheers!!