IPhone mkannotation:在地图加载后的左标注上的警告

Question

我有一个MKMapview加载也许5注释(现在)。它加载得很好，也有注解。每个注释都包含正确的左标注和右标注。然而，过了一段时间(也许2分钟)，我经常得到EXC_BAD_ACCESS崩溃，在注释的左侧callout…

- (MKAnnotationView *) mapView:(MKMapView *)thisMapView 
         viewForAnnotation:(MapAnnotations *)annotation
{
static NSString *MapIdentifier = @"MapIdentifier";
UIImageView *myImageView;
MKPinAnnotationView *annotationView = (MKPinAnnotationView *)[thisMapView dequeueReusableAnnotationViewWithIdentifier:MapIdentifier];
if(annotationView == nil)
{   
    NSString * id = [NSString stringWithFormat:@"%d", (annotation).tag];
    NSString * postPhoto = [NSString stringWithFormat:@"id=%@",id];
    NSString * hostStrPhoto = @"http://domain.com/get_image.php?";
    hostStrPhoto = [hostStrPhoto stringByAppendingString:postPhoto];
    NSData *imgData = [NSData dataWithContentsOfURL:[NSURL URLWithString:hostStrPhoto]];
    myImageView = [[UIImageView alloc] initWithImage:[UIImage imageWithData: imgData]];
    myImageView.frame = CGRectMake(0,0,31,31); 
    annotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:MapIdentifier] autorelease];
}
annotationView.animatesDrop=TRUE;

annotationView.canShowCallout = YES;
annotationView.leftCalloutAccessoryView = myImageView; //<--where I am getting the error, after all the annotations have loaded.
annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
return annotationView;
[myImageView autorelease]; 

}

我想也许我的应用程序仍在尝试加载注释，但我不知道为什么。当地图加载时，我也得到了一些内存警告，所以也许我没有像我应该的那样释放一些对象，我对内存管理的工作方式仍然是一种新的，所以任何建议都会有所帮助。

Answer 1

如果你最终重新使用注释视图，myImageView没有被创建，但你正在释放它。在顶部设置myImageView为nil。

- (MKAnnotationView *) mapView:(MKMapView *)thisMapView viewForAnnotation:(MapAnnotations *)annotation {
    static NSString *MapIdentifier = @"MapIdentifier";
    UIImageView *myImageView = nil;
    MKPinAnnotationView *annotationView = (MKPinAnnotationView *)[thisMapView dequeueReusableAnnotationViewWithIdentifier:MapIdentifier];
    if(annotationView == nil) {   
        NSString * id = [NSString stringWithFormat:@"%d", (annotation).tag];
        NSString * postPhoto = [NSString stringWithFormat:@"id=%@",id];
        NSString * hostStrPhoto = @"http://domain.com/get_image.php?";
        hostStrPhoto = [hostStrPhoto stringByAppendingString:postPhoto];
        NSData *imgData = [NSData dataWithContentsOfURL:[NSURL URLWithString:hostStrPhoto]];
        myImageView = [[UIImageView alloc] initWithImage:[UIImage imageWithData: imgData]];
        myImageView.frame = CGRectMake(0,0,31,31); 
        annotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:MapIdentifier] autorelease];
    }
    annotationView.animatesDrop=TRUE;
    annotationView.canShowCallout = YES;
    annotationView.leftCalloutAccessoryView = myImageView; //<--where I am getting the     error, after all the annotations have loaded.
    annotationView.rightCalloutAccessoryView = [UIButton     buttonWithType:UIButtonTypeDetailDisclosure];
    return annotationView;
    [myImageView release]; 
}