在mkmapview ios7中适合注释

Question

I am facing a zooming problem in MkMapView.When i am searching some stations,for the first time it zoom out properly and showing all annotation.But if i am searching the same station again it will shrink the MkMapView and not displaying all annotations.

This is my code to zoom annotation

#define MINIMUM_ZOOM_ARC 0.0001 //approximately 1 miles (1 degree of arc ~= 69 miles)
#define ANNOTATION_REGION_PAD_FACTOR 1.15
#define MAX_DEGREES_ARC 360

- (void)zoomMapViewToFitAnnotations:(MKMapView *)mapView animated:(BOOL)animated
{

    NSArray *annotations = mapView.annotations;
    int count = [mapView.annotations count];
    if ( count == 0) { return; } // mbail if no annotati  ons

    //convert NSArray of id <MKAnnotation> into an MKCoordinateRegion that can be used to set the map size
    //can't use NSArray with MKMapPoint because MKMapPoint is not an id
    MKMapPoint points[count]; //C array of MKMapPoint struct
    for( int i=0; i<count; i++ ) //load points C array by converting coordinates to points
    {
        CLLocationCoordinate2D coordinate = [(id <MKAnnotation>)[annotations objectAtIndex:i] coordinate];
        points[i] = MKMapPointForCoordinate(coordinate);
    }

//create MKMapRect from array of MKMapPoint
    MKMapRect mapRect = [[MKPolygon polygonWithPoints:points count:count] boundingMapRect];
//convert MKCoordinateRegion from MKMapRect
    MKCoordinateRegion region = MKCoordinateRegionForMapRect(mapRect);

//add padding so pins aren't scrunched on the edges
    region.span.latitudeDelta  *= ANNOTATION_REGION_PAD_FACTOR;
    region.span.longitudeDelta *= ANNOTATION_REGION_PAD_FACTOR;
//but padding can't be bigger than the world
    if( region.span.latitudeDelta > MAX_DEGREES_ARC ) { region.span.latitudeDelta  = MAX_DEGREES_ARC; }
    if( region.span.longitudeDelta > MAX_DEGREES_ARC ){ region.span.longitudeDelta = MAX_DEGREES_ARC; }

//and don't zoom in stupid-close on small samples
    if( region.span.latitudeDelta  < MINIMUM_ZOOM_ARC ) { region.span.latitudeDelta  = MINIMUM_ZOOM_ARC; }
    if( region.span.longitudeDelta < MINIMUM_ZOOM_ARC ) { region.span.longitudeDelta = MINIMUM_ZOOM_ARC; }
//and if there is a sample of 1 we want the max zoom-in instead of max zoom-out
    if( count == 1 )
    {
        region.span.latitudeDelta =0.05;
        region.span.longitudeDelta =0.05;

    }

    [mapView setRegion:region animated:animated];

}

Answer 1

您的问题被标记为showAnnotations:animated: 。在7中， MKMapView有一个新方法showAnnotations:animated:将视图缩放到提供的一组注释。