GPS routing (Shortest path) in iPhone using Mapkit and Google map - objective-c

Question

I am developing on Xcode 4.3.3, iOS 5 and using Mapkit library.
The app should show current location on Google map, get the destination address and finally draw the shortest path between those two points.
I used this tutorial for implementing the app and I have current location now:
http://blog.objectgraph.com/index.php/2009/04/02/iphone-sdk-30-playing-with-map-kit/
I looked for routing but I haven't found any resource.
Please guide me how I can draw the shortest path between the current location and the destination.
Thanks!

Answer 1

You can try this will only work for ios 6.
Class itemClass = [MKMapItem class];
if (itemClass && [itemClass respondsToSelector:#selector(openMapsWithItems:launchOptions:)]) {
CLGeocoder *geocoder = [[CLGeocoder alloc] init];
CLLocation *newLocation = [[CLLocation alloc]initWithLatitude:getLatitude
longitude:getLongitude];
[geocoder reverseGeocodeLocation:newLocation
completionHandler:^(NSArray *placemarks, NSError *error) {
MKPlacemark *placeMark = [[MKPlacemark alloc] initWithPlacemark:[placemarks objectAtIndex:0]];
MKMapItem *mapItem = [[MKMapItem alloc]initWithPlacemark:placeMark];
MKMapItem *mapItem2 = [MKMapItem mapItemForCurrentLocation];
NSArray *mapItems = #[mapItem, mapItem2];
NSDictionary *options = #{
MKLaunchOptionsDirectionsModeKey:MKLaunchOptionsDirectionsModeDriving,
MKLaunchOptionsMapTypeKey:
[NSNumber numberWithInteger:MKMapTypeStandard],
MKLaunchOptionsShowsTrafficKey:#YES
};
[MKMapItem openMapsWithItems:mapItems launchOptions:options];
} ];
}
else
{
UIAlertView *errorAlert = [[UIAlertView alloc] initWithTitle:#"Error" message:#"Failed to Get Your Location"delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[errorAlert show];
}
}

Answer 2

Did you google for map kit and route?
You'd find this: http://inlight.com.au/posts/mapkit which explains how to use Google Maps and decode the response to extract points to get a route.
There's also a commercial kit: http://mtdirectionsk.it/

Answer 3

iOS MapKit does not provide routing information for Apps as a service. Instead, your choices now are either to get routing information from a third-party mechanism, or to build the routes yourself (which, if you don't have the underlying street data is basically impossible).
You might look at CloudMade as an alternative map system if you need to provide routing information in your own App, or consider just calling Maps to route to a location if you want to take advantage of Apple's Map for navigation.
If you want to call out to the Map App for navigation, you basically need to open a URL with the source and destination location. Here's an example:
CLLocationManager *manager = [[[CLLocationManager alloc] init] autorelease];
CLLocationCoordinate2D currentLocation = [manager location].coordinate;
NSString *from = [NSString stringWithFormat: #"%f,%f",
currentLocation.latitude, currentLocation.longitude];
// used to be able to (3.2 iPad) "Current+Location", now we have to send: lat,long
NSString *encodedAddress = [address stringByAddingPercentEscapesUsingEncoding:
NSUTF8StringEncoding];
NSString *url = [NSString stringWithFormat:
#"http://maps.google.com/maps?saddr=%#&daddr=%#", from, encodedAddress];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];

Answer 4

Below ans work for all ios:
NSString *deviceVersion = [[UIDevice currentDevice] systemVersion];
NSLog(#"My Device version is :%# ",deviceVersion);
//********* For ios 6 supporting devices *********
if ([deviceVersion isEqualToString:#"6.0"])
{
Class itemClass = [MKMapItem class];
if (itemClass && [itemClass respondsToSelector:#selector(openMapsWithItems:launchOptions:)]) {
CLGeocoder *geocoder = [[CLGeocoder alloc] init];
CLLocation *newLocation = [[CLLocation alloc]initWithLatitude:getLatitude
longitude:getLongitude];
[geocoder reverseGeocodeLocation:newLocation
completionHandler:^(NSArray *placemarks, NSError *error) {
MKPlacemark *placeMark = [[MKPlacemark alloc] initWithPlacemark:[placemarks objectAtIndex:0]];
MKMapItem *mapItem = [[MKMapItem alloc]initWithPlacemark:placeMark];
MKMapItem *mapItem2 = [MKMapItem mapItemForCurrentLocation];
NSArray *mapItems = #[mapItem, mapItem2];
NSDictionary *options = #{
MKLaunchOptionsDirectionsModeKey:MKLaunchOptionsDirectionsModeDriving,
MKLaunchOptionsMapTypeKey:
[NSNumber numberWithInteger:MKMapTypeStandard],
MKLaunchOptionsShowsTrafficKey:#YES
};
[MKMapItem openMapsWithItems:mapItems launchOptions:options];
} ];
}
else
{
UIAlertView *errorAlert = [[UIAlertView alloc] initWithTitle:#"Error" message:#"Failed to Get Your Location"delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[errorAlert show];
}
}
//********* For other ios supporting devices *********
else {
MKCoordinateRegion region = { {0.0, 0.0 }, { 0.0, 0.0 } };
region.center.latitude = getLatitude;
region.center.longitude = getLongitude;
MKCoordinateRegion currentRegion = { {0.0, 0.0 }, { 0.0, 0.0 } };
currentRegion.center.latitude = currentLatitude;
currentRegion.center.longitude = currentLongitude;
region.span.longitudeDelta = 4.0f;
region.span.latitudeDelta = 4.0f;
currentRegion.span.longitudeDelta = 4.0f;
currentRegion.span.latitudeDelta = 4.0f;
CLLocationCoordinate2D start = { currentRegion.center.latitude, currentRegion.center.longitude };
CLLocationCoordinate2D destination = { region.center.latitude, region.center.longitude };
NSString *googleMapsURLString = [NSString stringWithFormat:#"http://maps.google.com/?saddr=%1.6f,%1.6f&daddr=%1.6f,%1.6f",start.latitude, start.longitude, destination.latitude, destination.longitude];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:googleMapsURLString]];
}
}