Question

我遇到了（我认为）这个mapView委托方法的问题：

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation

选择了引脚后，会显示一个标注。

当我移动地图以使引脚和标注不在视线范围内（两三个屏幕之外）或放大另一个区域时，它会缩放回选定的引脚。

我猜它正在这样做，因为引脚现在已经没有内存了，而且它正在被重新创建。在重新创建时，它正在被选中并且视图正在缩放。

如何让它不缩放？

下面的Anna K，问这个方法。我还粘贴了viewForAnnotation。

- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view {

     if ([view.annotation isKindOfClass:[MKUserLocation class]]) {
        // 
        NSLog(@"selected user loc");

    } else
    {

        selectedAnnotation = view.annotation;

        if (self.calloutAnnotation == nil) {
            self.calloutAnnotation = [[CalloutMapAnnotation alloc] initWithLatitude:view.annotation.coordinate.latitude
                                                                       andLongitude:view.annotation.coordinate.longitude];
        } else {
            self.calloutAnnotation.latitude = view.annotation.coordinate.latitude;
            self.calloutAnnotation.longitude = view.annotation.coordinate.longitude;
        }

        // this doesn't allow user to click away from selected pin to another
        // [self.mapView  addAnnotation:self.calloutAnnotation];
        // this fixes it
        [self.mapView performSelector:@selector(addAnnotation:) withObject:self.calloutAnnotation afterDelay:0.005];

        self.selectedAnnotationView = view;
        BasicMapAnnotationView *tempAnnView = (BasicMapAnnotationView *)view;
        selectedPin = tempAnnView.tag;


    }

}





- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {

    originalRegion = self.mapView.region;
    if (annotation == self.calloutAnnotation) {

        NSPredicate *searchPredicate = [NSPredicate predicateWithFormat:@"storeID == %@", [NSNumber numberWithInt:selectedPin]];
        NSMutableArray* mutableFetchResults = [CoreDataHelper searchObjectsInContext:@"Store" :searchPredicate :@"storeName" :YES :self.managedObjectContext];

        if ([mutableFetchResults count] > 0)
        {
            Singleton *singleton = [Singleton sharedSingleton];
            Store *tempStore = (Store*)[mutableFetchResults objectAtIndex:0]; 
            if (tempStore.storeIsPicked == [NSNumber numberWithBool:YES]) {
                singleton.isPicked = YES;
            } else
            {
                singleton.isPicked = NO;
            }

        }


            AccessorizedCalloutMapAnnotationView *calloutMapAnnotationView = [[[AccessorizedCalloutMapAnnotationView alloc] initWithAnnotation: annotation reuseIdentifier: @"CalloutAnnotation"] autorelease];
    calloutMapAnnotationView.contentHeight = 40.0;


            if ([mutableFetchResults count] > 0)
            {

                Store *store = (Store*)[mutableFetchResults objectAtIndex:0];  

                UILabel *shopName = [[UILabel alloc] initWithFrame:CGRectMake(36, -3, 250, 29)];
                shopName.font = [UIFont boldSystemFontOfSize:14.0];
                shopName.text = store.storeName;
                shopName.backgroundColor= [UIColor clearColor];

                UILabel *addressName = [[UILabel alloc] initWithFrame:CGRectMake(36, 13, 250, 29)];
                addressName.font = [UIFont systemFontOfSize:9.0];
                addressName.textColor = [UIColor lightGrayColor];
                addressName.text = store.storeAddress;
                addressName.backgroundColor= [UIColor clearColor];

                [calloutMapAnnotationView.contentView addSubview:shopName];
                [calloutMapAnnotationView.contentView addSubview:addressName];

                calloutMapAnnotationView.parentAnnotationView = self.selectedAnnotationView;

                [shopName release];
                [addressName release];
                calloutMapAnnotationView.mapView = self.mapView;
                return calloutMapAnnotationView;
            } else 
            {
                NSLog(@"returning nil .. no stores");
                return nil;
            }



    } 

    else 
    {

        if ([annotation isKindOfClass:[MKUserLocation class]])
        {
            // do something with blue dot?

        }
        else
        {

            BasicMapAnnotationView *annotationView = [[[BasicMapAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"CustomAnnotation"] autorelease];
            BasicMapAnnotation *tempAn = (BasicMapAnnotation *)annotation;



            if ([annotation isKindOfClass:[BasicMapAnnotation class]])
                {
                NSPredicate *searchPredicate = [NSPredicate predicateWithFormat:@"storeID == %@", [NSNumber numberWithInt:tempAn.mapTag]];

                NSMutableArray* mutableFetchResults = [CoreDataHelper searchObjectsInContext:@"Store" :searchPredicate :@"storeName" :YES :self.managedObjectContext];

                if ([mutableFetchResults count]>0)
                {
                    Store *store = [mutableFetchResults objectAtIndex:0];

                    BOOL isPicked = [store.storeIsPicked boolValue];
                    if (isPicked)
                    {
                        annotationView.image = [UIImage imageNamed:@"pinPicked.png"];


                    } else  
                    {
                        annotationView.image = [UIImage imageNamed:@"pinOff.png"];


                    }
                    annotationView.centerOffset = CGPointMake(-8, -9);
                    annotationView.canShowCallout = NO;
                    annotationView.tag = tempAn.mapTag;
                    return annotationView;
                } 
                } 
        }
    }


    return nil;
}

Answer 1

我以前遇到过这个问题，问题是您的地图区域是由引脚位置定义的。您应该将viewDidLoad方法中的mapView setRegion代码更改为所需的位置，然后根据用户位置或任何需要进行更新。

- (void)viewDidLoad{
[super viewDidLoad];

// define span for map: how much area will be shown
MKCoordinateSpan span;
span.latitudeDelta = 0.002;
span.longitudeDelta = 0.002;

// define starting point for map
CLLocationCoordinate2D start;
start.latitude = 42.36873056998856; //Change to what you desire for starting point
start.longitude = -71.11504912376404; //Could also be set to user or pin Location if desired

// create region, consisting of span and location
MKCoordinateRegion region;
region.span = span;
region.center = start;

// move the map to our location
[self.mapView setRegion:region animated:YES];
}

不需要缩放回选定的地图引脚

1 个答案: