How can I launch the Google Maps iPhone application from within my own native application?

Question

The Apple Developer Documentation (link is dead now) explains that if you place a link in a web page and then click it whilst using Mobile Safari on the iPhone, the Google Maps application that is provided as standard with the iPhone will launch.

How can I launch the same Google Maps application with a specific address from within my own native iPhone application (i.e. not a web page through Mobile Safari) in the same way that tapping an address in Contacts launches the map?

NOTE: THIS ONLY WORKS ON THE DEVICE ITSELF. NOT IN THE SIMULATOR.

Answer 1

For iOS 5.1.1 and lower, use the openURL method of UIApplication. It will perform the normal iPhone magical URL reinterpretation. so

[someUIApplication openURL:[NSURL URLWithString:@"http://maps.google.com/maps?q=London"]] 

should invoke the Google maps app.

From iOS 6, you'll be invoking Apple's own Maps app. For this, configure an MKMapItem object with the location you want to display, and then send it the openInMapsWithLaunchOptions message. To start at the current location, try:

[[MKMapItem mapItemForCurrentLocation] openInMapsWithLaunchOptions:nil]; 

You'll need to be linked against MapKit for this (and it will prompt for location access, I believe).

Answer 2

Exactly. The code that you need to achieve this is something like that:

UIApplication *app = [UIApplication sharedApplication]; [app openURL:[NSURL URLWithString: @"http://maps.google.com/maps?q=London"]]; 

since as per the documentation, UIApplication is only available in the Application Delegate unless you call sharedApplication.