iphone 地图定位

CLLocationCoordinate2D loc = [newLocation coordinate];
　　[[UIApplication sharedApplication] openURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://maps.google.com/maps?saddr=%f,%f&daddr=%@",loc.latitude,loc.longitude,@"中国,湖南,长沙,具体地名"]]];