刷新地图后错误的图像MKAnnotationView

Question

我有一个mapview数百个注释.我在后台加载注释,当加载所有注释时,我调用方法:setAnnotations.

我有6种类型的注释,彼此不同的引脚.

它适用于第一次装载.但是如果我想刷新地图(因为我使用过滤器),则图像图像会发生变化.

我在这里看到了类似的问题,但似乎对我不起作用.

这里是我的viewForAnnotation方法:

//... 
else if ([annotation isKindOfClass:[CustomAnnotation class]]) {

        CustomAnnotation *singleAnnotation = (CustomAnnotation *)annotation;
        annotationView = (MKAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"singleAnnotationView"];

        if (!annotationView) {
            annotationView = [[MKAnnotationView alloc] initWithAnnotation:singleAnnotation reuseIdentifier:@"singleAnnotationView"];
            annotationView.canShowCallout = YES;
            annotationView.centerOffset = CGPointMake(0, -20);
            annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        }
        else
            annotationView.annotation = annotation;

// Solution, put it here:
annotationView.image = [UIImage imageNamed:[NSString stringWithFormat:@"pin_%d", singleAnnotation.idType]];
    } 
//...

在这里我调用加载和重新加载地图的方法:

- (void)loadMapView
{
    UIActivityIndicatorView *a = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    self.mapview.hidden = YES;
    a.center = CGPointMake(160, 240);
    [self.view addSubview:a];
    [a startAnimating];

    NSMutableArray *array = [NSMutableArray new];

    if(self.mapview.annotations.count > 0){
        [self.mapview removeAnnotations:self.mapview.annotations];
        [self.mapview removeOverlays:self.mapview.overlays];
    }

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{

        for(MapObjects *obj in [MapRepository shared].repository){

            CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(obj.coord_geo_latitude,obj.coord_geo_longitude);

            CustomAnnotation *annotation = [[CustomAnnotation alloc] initWithCoordinates:coordinate
                                                                               placeName:obj.placeName
                                                                             description:obj.description
idType:obj.idType];

            if(annotation.coordinate.latitude != 0 || annotation.coordinate.longitude != 0)
                [array addObject:annotation];
        }

        dispatch_async(dispatch_get_main_queue(), ^{

            [self.mapview addAnnotations:array];
            [self.mapview zoomToFitMapAnnotations:self.mapview];
            [a stopAnimating];
            self.mapview.hidden = NO;
        });
    });  
}

我做错了什么？

任何建议和帮助都很感激.先感谢您 ;)

Answer 1

问题是地图视图将重复使用具有相同重用标识符的引脚.这就是你创建引脚的方式:

annotationView = [[MKAnnotationView alloc] initWithAnnotation:singleAnnotation
                                              reuseIdentifier:@"singleAnnotationView"];

随后,您设置图像.有两种可能的解决方案:

1. 为每种图像类型使用不同的重用标识符.这样,这些引脚将根据需要进行缓存.
2. 创建后在引脚上设置图像.这样,所有引脚都进入相同的重用池,并根据需要进行自定义.

这是#2的样子:

CustomAnnotation *singleAnnotation = (CustomAnnotation *)annotation;
annotationView = (MKAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:@"singleAnnotationView"];

if (!annotationView) {
    annotationView = [[MKAnnotationView alloc] initWithAnnotation:singleAnnotation reuseIdentifier:@"singleAnnotationView"];
    annotationView.canShowCallout = YES;
    annotationView.centerOffset = CGPointMake(0, -20);
    annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
}
else {
    annotationView.annotation = annotation;
}

annotationView.image = [UIImage imageNamed:[NSString stringWithFormat:@"pin_%d", singleAnnotation.idType]];