iOS MKMapView de zoom pour afficher tous les marqueurs

Sûr. Vous souhaitez trouver les plus grandes et les plus petites valeurs de latitude et longitude parmi vos annotations (que vous pouvez le faire par itération sur la carte.les annotations), puis définissez la carte pour afficher tous les d'entre eux.

//pad our map by 10% around the farthest annotations
#define MAP_PADDING 1.1

//we'll make sure that our minimum vertical span is about a kilometer
//there are ~111km to a degree of latitude. regionThatFits will take care of
//longitude, which is more complicated, anyway. 
#define MINIMUM_VISIBLE_LATITUDE 0.01

MKCoordinateRegion region;
region.center.latitude = (minLatitude + maxLatitude) / 2;
region.center.longitude = (minLongitude + maxLongitude) / 2;

region.span.latitudeDelta = (maxLatitude - minLatitude) * MAP_PADDING;

region.span.latitudeDelta = (region.span.latitudeDelta < MINIMUM_VISIBLE_LATITUDE)
    ? MINIMUM_VISIBLE_LATITUDE 
    : region.span.latitudeDelta;

region.span.longitudeDelta = (maxLongitude - minLongitude) * MAP_PADDING;

MKCoordinateRegion scaledRegion = [map regionThatFits:region];
[map setRegion:scaledRegion animated:YES];

Ici est une amélioration qui prend en compte la hauteur des vues d'annotations que vous êtes en superposition sur la carte (tels que le haut de l'annotation n'a pas coupé lorsque ses coordonnées décalage est en bas par exemple). Ou de généraliser de plus, vous permet de spécifier un rembourrage en pixels plutôt qu'un pourcentage. Il nécessite deux étapes passent par lequel vous trouverez les valeurs limites pour les annotations, puis vous augmenter encore les limites de tenir compte de votre carte de rembourrage.

- (void) zoomToAnnotationsBounds:(NSArray *)annotations {
CLLocationDegrees minLatitude = DBL_MAX;
CLLocationDegrees maxLatitude = -DBL_MAX;
CLLocationDegrees minLongitude = DBL_MAX;
CLLocationDegrees maxLongitude = -DBL_MAX;
for (MyAnnotation *annotation in annotations) {
double annotationLat = annotation.coordinate.latitude;
double annotationLong = annotation.coordinate.longitude;
minLatitude = fmin(annotationLat, minLatitude);
maxLatitude = fmax(annotationLat, maxLatitude);
minLongitude = fmin(annotationLong, minLongitude);
maxLongitude = fmax(annotationLong, maxLongitude);
}
//See function below
[self setMapRegionForMinLat:minLatitude minLong:minLongitude maxLat:maxLatitude maxLong:maxLongitude];
//If your markers were 40 in height and 20 in width, this would zoom the map to fit them perfectly. Note that there is a bug in mkmapview's set region which means it will snap the map to the nearest whole zoom level, so you will rarely get a perfect fit. But this will ensure a minimum padding.
UIEdgeInsets mapPadding = UIEdgeInsetsMake(40.0, 10.0, 0.0, 10.0);
CLLocationCoordinate2D relativeFromCoord = [self.mapView convertPoint:CGPointMake(0, 0) toCoordinateFromView:self.mapView];
//Calculate the additional lat/long required at the current zoom level to add the padding
CLLocationCoordinate2D topCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.top) toCoordinateFromView:self.mapView];
CLLocationCoordinate2D rightCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.right) toCoordinateFromView:self.mapView];
CLLocationCoordinate2D bottomCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.bottom) toCoordinateFromView:self.mapView];
CLLocationCoordinate2D leftCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.left) toCoordinateFromView:self.mapView];
double latitudeSpanToBeAddedToTop = relativeFromCoord.latitude - topCoord.latitude;
double longitudeSpanToBeAddedToRight = relativeFromCoord.latitude - rightCoord.latitude;
double latitudeSpanToBeAddedToBottom = relativeFromCoord.latitude - bottomCoord.latitude;
double longitudeSpanToBeAddedToLeft = relativeFromCoord.latitude - leftCoord.latitude;
maxLatitude = maxLatitude + latitudeSpanToBeAddedToTop;
minLatitude = minLatitude - latitudeSpanToBeAddedToBottom;
maxLongitude = maxLongitude + longitudeSpanToBeAddedToRight;
minLongitude = minLongitude - longitudeSpanToBeAddedToLeft;
[self setMapRegionForMinLat:minLatitude minLong:minLongitude maxLat:maxLatitude maxLong:maxLongitude];
}
-(void) setMapRegionForMinLat:(double)minLatitude minLong:(double)minLongitude maxLat:(double)maxLatitude maxLong:(double)maxLongitude {
MKCoordinateRegion region;
region.center.latitude = (minLatitude + maxLatitude) / 2;
region.center.longitude = (minLongitude + maxLongitude) / 2;
region.span.latitudeDelta = (maxLatitude - minLatitude);
region.span.longitudeDelta = (maxLongitude - minLongitude);
//MKMapView BUG: this snaps to the nearest whole zoom level, which is wrong- it doesn't respect the exact region you asked for. See http://stackoverflow.com/questions/1383296/why-mkmapview-region-is-different-than-requested
[self.mapView setRegion:region animated:YES];
}

Modifié Répondre à tous Parfaits Code de Travail.

//Zooming the ploted Area
- (void)zoomToAnnotationsBounds:(NSArray *)latLongArray {
__block CLLocationDegrees minLatitude = DBL_MAX;
__block CLLocationDegrees maxLatitude = -DBL_MAX;
__block CLLocationDegrees minLongitude = DBL_MAX;
__block CLLocationDegrees maxLongitude = -DBL_MAX;
[latLongArray enumerateObjectsUsingBlock:^(NSString *latLongObj, NSUInteger latLongIdx, BOOL *stop) {
latLongObj = [latLongArray objectAtIndex:latLongIdx];
NSArray *latLongPoint = [latLongObj componentsSeparatedByString:@","];
double annotationLat = [[latLongPoint objectAtIndex:0] doubleValue];
double annotationLong = [[latLongPoint objectAtIndex:1] doubleValue];
minLatitude = fmin(annotationLat, minLatitude);
maxLatitude = fmax(annotationLat, maxLatitude);
minLongitude = fmin(annotationLong, minLongitude);
maxLongitude = fmax(annotationLong, maxLongitude);
}];
[self setMapRegionForMinLat:minLatitude minLong:minLongitude maxLat:maxLatitude maxLong:maxLongitude];
}
-(void) setMapRegionForMinLat:(double)minLatitude minLong:(double)minLongitude maxLat:(double)maxLatitude maxLong:(double)maxLongitude {
//pad our map by 10% around the farthest annotations
//we'll make sure that our minimum vertical span is about a kilometer
//there are ~111km to a degree of latitude. regionThatFits will take care of
//longitude, which is more complicated, anyway.
MKCoordinateRegion region;
region.center.latitude = (minLatitude + maxLatitude) / 2;
region.center.longitude = (minLongitude + maxLongitude) / 2;
region.span.latitudeDelta = (maxLatitude - minLatitude) * MAP_PADDING;
region.span.latitudeDelta = (region.span.latitudeDelta < MINIMUM_VISIBLE_LATITUDE)
? MINIMUM_VISIBLE_LATITUDE
: region.span.latitudeDelta;
region.span.longitudeDelta = (maxLongitude - minLongitude) * MAP_PADDING;
MKCoordinateRegion scaledRegion = [regionsMapView regionThatFits:region];
[regionsMapView setRegion:scaledRegion animated:YES];
}