左侧标注图像未显示在MKMapView注释视图中

Question

我不知道我做错了什么,但它不会工作.

我mapView: viewForAnnotation:看起来像这样:

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    MKAnnotationView *aView = [mapView dequeueReusableAnnotationViewWithIdentifier:@"ImageMapView"];
    if (!aView)
    {
        aView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"ImageMapView"];
        aView.canShowCallout = YES;
        aView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        aView.leftCalloutAccessoryView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
    }
    [(UIImageView *)aView.leftCalloutAccessoryView setImage:nil];
    aView.annotation = annotation;
    return aView;
}

所以每个新的注释都以左侧标注中的空白图像视图开始.

现在当触摸标注时,执行下一个代码:

- (void)mapView:(MKMapView *)mapView didDeselectAnnotationView:(MKAnnotationView *)view
{
    //loading an image
    [(UIImageView *)view.leftCalloutAccessoryView setImage:image];
}

在日志记录的帮助下,我知道图像的网址和数据都没问题,图像本身也不是零,但左侧标注中没有显示任何内容.

任何人都可以建议我如何追查这个问题的根源？

编辑

我添加了一些日志,所以我可以看到发生了什么:

- (void)mapView:(MKMapView *)mapView didDeselectAnnotationView:(MKAnnotationView *)view
{
    UIImage *image = [self.delegate imagesMapViewController:self thumbnailForAnnotation:view.annotation];
    NSLog(@"Image was: %@", [(UIImageView *)view.leftCalloutAccessoryView image]);
    NSLog(@"Image received: %@", image);
    [(UIImageView *)view.leftCalloutAccessoryView setImage:image];
    NSLog(@"Image became: %@", [(UIImageView *)view.leftCalloutAccessoryView image]);
}

我最终得到了下一个输出:

Image was: (null)
Image received: <UIImage: 0x7933470>
Image became: <UIImage: 0x7933470>

所以图像正在设置,但没有出现,我不明白为什么.此外,第一个日志记录信息仅在第二个注释视图被录制后出现,因此第一个注释视图未调用是很不寻常的mapView: didDeselectAnnotationView:

当我放的时候

[(UIImageView *)aView.leftCalloutAccessoryView setImage:[self.delegate imagesMapViewController:self thumbnailForAnnotation:aView.annotation]];

代替

[(UIImageView *)aView.leftCalloutAccessoryView setImage:nil];

在mapView: viewForAnnotation:所有左侧标注配件有他们应该的图像,但离开源我想按需下载图像

Answer 1

问题是,你使用

- (void)mapView:(MKMapView *)mapView didDeselectAnnotationView:(MKAnnotationView *)view

什么时候应该使用

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

干杯)