sample code for Location finder in iphone

I am trying to make an app which uses both the GPS a开发者_如何学Gond the magnetometer for finding the way and direction for mecca (Mosque). It has some special features like date picker for upcoming prayers, prayer timings left calculated from current location time zone and weather on the current location and some more on. If anyone has sample code regarding to this, please reply.

Thanks in advance

The magnetometer can be told just to return the current device heading, via CLLocationManager. It can return in unfiltered 3d, but there's no reason to use it — from CLHeading just use the trueHeading property. That'll give you the same information shown in the Compass app.

To work out the heading to Mecca from where you are, you can use the formulas given here. Google Maps gives me a geolocation of about 21.436, 39.832 for Masjid al-Haram (I'm not sure it's terribly accurate, so I've rounded inappropriately low), so you could get the bearing from whatever location CLLocationManager tells you you're at something like:

#define toRadians(x) ((x)*M_PI / 180.0)
#define toDegrees(x) ((x)*180.0 / M_PI)

...

double y = sin(toRadians(39.832 - currentLocation.longitude)) * cos(toRadians(21.436));
double x = cos(toRadians(currentLocation.latitude)) * dsin(toRadians(21.436)) -
           sin(toRadians(currentLocation.latitude)) * dcos(toRadians(21.436)) * dcos(toRadians(39.832 - currentLocation.longitude));
double bearing = toDegrees(atan2(y, x));

You can then rotate a pointer on screen by the difference between the device's heading and the one you've just calculated. Probably easiest to use a CGAffineTransform on a UIView's transform property.

That's all typed as I answer by the way, not tested. I'd check it against a reliable source before you depend on it.