How do you get the current location of iPhone through code? I need to track the location using GPS.
You're looking for the "CoreLocation" API.
Here's a tutorial
There is (as always for core functionality) comprehensive documentation on the developer site and you may find this example useful;
The key points to remember are;
1) Once you start receiving location updates, they arrive asynchronously and you need to respond to them as and when they come in. Check the accuracy and timestamps to decide if you want to use the location or not.
2) Don't forget to stop receiving updates as soon as you have the location you want (this might not be the first one), otherwise you will drain the battery life.
3) The first location returned to you is often the LAST CACHED one, and the phone will report this location with the same (possibly high) accuracy it had when it got the fix before. So you might get a fix that claims to be accurate to 10 metres but it was actually received yesterday when you were miles away from your current location. The motto of this is DON'T FORGET TO CHECK THE TIMESTAMP - this tells you when the location fix was actually received. Here's an example of how to check the timestamp.
Hope that helps.
This page on CLLocationManager has five source code examples
download this example it will show you current location
If you just need to get the device's current location, using Core Location directly requires a good deal of code because you must handle the delay until the device's GPS has an accurate fix on the current location, which takes a number of seconds. (The CLLocationManager API appears to be built for apps that need continuous location updates, like turn-by-turn GPS navigation apps.)
Instead of using CLLocationManager directly, I suggest you take a look at using an open source component such as INTULocationManager which will handle all of this work for you and make it trivially simple to request one or more discrete requests for the device's current location.
The real solution can be found here. Z5 Concepts iOS Development Code Snippet
It just requires a little bit of encoding.
NSString* address = @"118 Your Address., City, State, ZIPCODE";
NSString* currentLocation = @"Current Location";
NSString* url = [NSStringstringWithFormat: @"http://maps.google.com/maps?saddr=%@&daddr=%@",[currentLocation stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],[address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
UIApplication *app = [UIApplicationsharedApplication];
[app openURL: [NSURL URLWithString: url]];