Passing location to different view with segue - iphone

Question

very very new to iOS programming, so I appreciate any help with this.
All I actually want to do is pass the variable of my current coordinates to a different view when a button is pressed. I can't work out how to do this using my current work - I'm getting in a total muddle. My project is essentially made from lots of chunks of code from various sources. I'll share with you the parts that I think are relevant, and hopefully somebody can at least point me in the right direction!
This is from my MainViewController.m:
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
if (currentPosition == nil) {
MKMapPoint point = MKMapPointForCoordinate(newLocation.coordinate);
double pointsPerMeter = MKMapPointsPerMeterAtLatitude(newLocation.coordinate.latitude);
double visibleDistance = pointsPerMeter * 500.0;
MKMapRect rect = MKMapRectMake(
point.x - visibleDistance, point.y - visibleDistance,
visibleDistance * 2, visibleDistance * 2);
[self.mapView setVisibleMapRect:rect animated:YES];
NSURL *url = [NSURL URLWithString:#"https://url.url/json.json"];
NSData *data = [NSData dataWithContentsOfURL:url];
NSError *error;
NSArray *array = [NSJSONSerialization JSONObjectWithData:data
options:0
error:&error];
if (error != nil)
{
}
CLLocationCoordinate2D location;
NSMutableArray *newAnnotations = [NSMutableArray array];
MKPointAnnotation *newAnnotation;
for (NSDictionary *dictionary in array)
{
location.latitude = [dictionary[#"lat"] doubleValue];
location.longitude = [dictionary[#"lon"] doubleValue];
newAnnotation = [[MKPointAnnotation alloc] init];
newAnnotation.coordinate = location;
HUWMapAnnotation *annotation = [[HUWMapAnnotation alloc] initWithCoordinate:newAnnotation.coordinate];
annotation.messagetitle = dictionary[#"name"];
annotation.email = dictionary[#"message"];
annotation.username = dictionary[#"user"];
[self.mapView addAnnotation:annotation];
[newAnnotations addObject:newAnnotation];
}
}
currentPosition = newLocation;
}
- (void)viewDidLoad { [super viewDidLoad];
// Check if the user has enabled location services.
if ([CLLocationManager locationServicesEnabled]) {
// Create a location manager.
locationManager = [[CLLocationManager alloc] init];
// Set ourselves as it's delegate so that we get notified of position updates.
locationManager.delegate = self;
// Set the desired accuracy.
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
// Start tracking.
[locationManager startUpdatingLocation];
}
}
Like I said, I've trimmed this down substantially to the bits I think are relevant. Let me know if I have missed something essential. I've got my storyboard set up with a button ready to go, and a segue with its identifier.
I assume that I should be using prepareForSegue - but my issue is that I quite simply don't know how to get my coordinates into that situation.
I hope somebody will be able to help me (and I apologise for the large amount of copy-pasted code!)

Answer 1

To pass objects between view controllers using segues, do something like the following:
1) create a segue between the source and destination view controllers in IB, give it an identifier #"MySegue".
2) let's say the destination vc needs a string to run:
// DestinationVC.h
#interface DestinationVC : UIViewController
#property(strong, nonatomic) NSString *string;
#end
3) the source vc initiates a segue:
[self performSegueWithIdentifier:#"MySegue" sender:self];
4) the source vc prepares by initializing the property on the destination vc:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"MySegue"]) {
DestinationVC *vc = [segue destinationViewController];
vc.string = // some object that the source vc has. this could be your CLLocationCoordinate2D
}
}