Cannot get UIMapView to “zoom”/setRegion: when the map is loaded for the first time

问题

I have a UIViewController that loads a map with a bunch of pins already on it. There's no issues getting the pins to appear, but I can't seem to get MKMapView to execute setRegion when the user first reaches the mapView. I've tried putting the code in every possible method that could work, viewDidLoad, viewWillLoad, mapViewWillStartLoadingMap, mapViewDidFinishLoadingMap, etc., to no avail.

And yet, it WILL "zoom" to the designated region if I return to the previous viewController and then go into the viewContoller containing the mapView again.

Is there a super secret way of doing this that I'm not aware of? Shouldn't calling [mapView setRegion:(...) animated:YES]; be enough to get the map to "zoom"/update to show the chosen region??

Also, if anybody knows how to get the pins (I'm using MKPointAnnotation for mine) to animate dropping in as well as getting the map to animate zooming in, (neither are doing it, although I set both to animate....), I'd appreciate that info as well.

Thanks!

Code:

@implementation FindOnMapMapView
@synthesize mapView;
@synthesize mapViewTabBarItem;
@synthesize results;
@synthesize reverseGeocoder;

    - (void)viewDidLoad
    {
        [super viewDidLoad];

        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

        MKCoordinateRegion mapRegion = MKCoordinateRegionMake(CLLocationCoordinate2DMake([defaults doubleForKey:@"latitude"], [defaults doubleForKey:@"longitude"]), MKCoordinateSpanMake(0.744494189288569, 0.744494189288569));

        mapView.region = mapRegion;
        [mapView setRegion:mapRegion animated:YES];



NSMutableArray *annotations = [[NSMutableArray alloc] init];
        for(ThePlace *place in results)
        {
            MKPointAnnotation *addAnnotation = [[MKPointAnnotation alloc] init];

            [addAnnotation setCoordinate:CLLocationCoordinate2DMake(place.latitude, place.longitude)];

            addAnnotation.title = place.placename;
            addAnnotation.subtitle = [NSString stringWithFormat:@"Distance: %@", place.distance];

            [mapView addAnnotation:addAnnotation];

        }

        [self.mapView addAnnotations:annotations ];
    }

    - (void)viewWillAppear:(BOOL)animated
    {
        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

        MKCoordinateRegion mapRegion = MKCoordinateRegionMake(CLLocationCoordinate2DMake([defaults doubleForKey:@"latitude"], [defaults doubleForKey:@"longitude"]), MKCoordinateSpanMake(0.744494189288569, 0.744494189288569));
        NSLog(@"Region Coords are: Latitude:%f, Longitude:%f", [defaults doubleForKey:@"latitude"], [defaults doubleForKey:@"longitude"]);
        mapView.region = mapRegion;
        [mapView setRegion:mapRegion animated:YES];
    }

回答1:

- (void) viewDidAppear:(BOOL)animated {
    MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(firstPoint.coordinate, 2000, 2000);
    [mapView setRegion:region animated:YES];
}

This works for me.

来源：https://stackoverflow.com/questions/13017461/cannot-get-uimapview-to-zoom-setregion-when-the-map-is-loaded-for-the-first-t

标签

iphone

ios

mkmapview

mapkit