Zoom to Fit Current Location and Annotation on Map

Zoom to fit current location and annotation on map

MKMapRectUnion computes and returns a new rect, nothing more. You need to tell the mapView to set its visible area to that new rect:

myMapView.setVisibleMapRect(zoomRect, animated: true)

Zooming MKMapView to fit annotation pins?

You've got it right.

Find your maximum and minimum latitudes and longitudes, apply some simple arithmetic, and use MKCoordinateRegionMake.

For iOS 7 and above, use showAnnotations:animated:, from MKMapView.h:

// Position the map such that the provided array of annotations are all visible to the fullest extent possible. 
- (void)showAnnotations:(NSArray *)annotations animated:(BOOL)animated NS_AVAILABLE(10_9, 7_0);

Making the map zoom to user location and annotation (swift 2)

It just jumps right back to the user's location, because didUpdateLocations method is called many times. There are two solutions.

1) Use requestLocation

If you use requestLocation method instead of startUpdatingLocation, didUpdateLocations method is called only once

if #available(iOS 9.0, *) {
    locationManager.requestLocation()
} else {
    // Fallback on earlier versions
}

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    let userLoction: CLLocation = locations[0]
    let latitude = userLoction.coordinate.latitude
    let longitude = userLoction.coordinate.longitude
    let latDelta: CLLocationDegrees = 0.05
    let lonDelta: CLLocationDegrees = 0.05
    let span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, lonDelta)
    let location: CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude)
    let region: MKCoordinateRegion = MKCoordinateRegionMake(location, span)
    self.map.setRegion(region, animated: true)
    self.map.showsUserLocation = true
}

2) Use flag

var isInitialized = false

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    if !isInitialized {
        // Here is called only once
        isInitialized = true

        let userLoction: CLLocation = locations[0]
        let latitude = userLoction.coordinate.latitude
        let longitude = userLoction.coordinate.longitude
        let latDelta: CLLocationDegrees = 0.05
        let lonDelta: CLLocationDegrees = 0.05
        let span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, lonDelta)
        let location: CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude)
        let region: MKCoordinateRegion = MKCoordinateRegionMake(location, span)
        self.map.setRegion(region, animated: true)
        self.map.showsUserLocation = true
    }
}

MapKit zoom to user current location

I faced similar issue and wasted 4 days thinking whats going wrong. Finally resolved with creating these lines of code in viewDidLoad Method :

    //Zoom to user location
    let noLocation = CLLocationCoordinate2D()
    let viewRegion = MKCoordinateRegionMakeWithDistance(noLocation, 200, 200)
    mapView.setRegion(viewRegion, animated: false)
    mapView.showsUserLocation = true

In ViewDidLoad Method add these new changes code :

override func viewDidLoad() {

    super.viewDidLoad()

    let locationManager = CLLocationManager()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest

    // Check for Location Services
    if (CLLocationManager.locationServicesEnabled()) {
        locationManager.requestAlwaysAuthorization()
        locationManager.requestWhenInUseAuthorization()
    }

    //Zoom to user location
    if let userLocation = locationManager.location?.coordinate {
        let viewRegion = MKCoordinateRegionMakeWithDistance(userLocation, 200, 200)
        mapView.setRegion(viewRegion, animated: false)
    }

    self.locationManager = locationManager

    DispatchQueue.main.async {
        self.locationManager.startUpdatingLocation()
    }

}

Hope this helps to resolve your issue. Feel free to post comment if any further issue. Thanks

What's the best way to zoom out and fit all annotations in MapKit

-(void)zoomToFitMapAnnotations:(MKMapView*)mapView
{
    if([mapView.annotations count] == 0)
        return;

    CLLocationCoordinate2D topLeftCoord;
    topLeftCoord.latitude = -90;
    topLeftCoord.longitude = 180;

    CLLocationCoordinate2D bottomRightCoord;
    bottomRightCoord.latitude = 90;
    bottomRightCoord.longitude = -180;

    for(MapAnnotation* annotation in mapView.annotations)
    {
        topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
        topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);

        bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
        bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
    }

    MKCoordinateRegion region;
    region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5;
    region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;
    region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1; // Add a little extra space on the sides
    region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1; // Add a little extra space on the sides

    region = [mapView regionThatFits:region];
    [mapView setRegion:region animated:YES];
}

Taken from: http://codisllc.com/blog/zoom-mkmapview-to-fit-annotations/

(Use it all the time.)

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