Ios EXC_访问错误-NSFETCHEEDRESULTSCONTROLLER、UITableViewController、UINavigationController、UIPOPCOVERCONTROLLER
我有一个Ios EXC_访问错误-NSFETCHEEDRESULTSCONTROLLER、UITableViewController、UINavigationController、UIPOPCOVERCONTROLLER,ios,cocoa-touch,core-data,automatic-ref-counting,Ios,Cocoa Touch,Core Data,Automatic Ref Counting,我有一个UITableViewController在UINavigationController中,在UIPopoverController中 - (NSFetchedResultsController *) myFetchedResultsController { if (self.fetchedResultsController != nil) { return self.fetchedResultsController; } // Sin
UITableViewController
在UINavigationController
中,在UIPopoverController
中
- (NSFetchedResultsController *) myFetchedResultsController
{
if (self.fetchedResultsController != nil) {
return self.fetchedResultsController;
}
// Singleton
CoreDataManager * dataManager = [CoreDataManager defaultDataManager];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Bookmark" inManagedObjectContext:dataManager.managedObjectContext];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"label" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setEntity:entity];
[fetchRequest setPredicate:self.predicate];
[fetchRequest setSortDescriptors:sortDescriptors];
[fetchRequest setFetchBatchSize:20]; // Set the batch size to a suitable number.
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:dataManager.managedObjectContext
sectionNameKeyPath:@"type"
cacheName:nil];
self.fetchedResultsController.delegate = self;
return self.fetchedResultsController;
}
UITableViewController
使用NSFetchedResultsController
。didSelectRowAtIndexPath将另一个带有略微不同谓词的myUITableViewController
实例推送到导航控制器堆栈上
如果我将一个新的UITableViewController
推到堆栈上,然后再次弹出它,如果我试图保存一个会更新弹出的tableview的对象,我最终将获得一个EXC\u BAD\u访问权
正如预期的那样,将myNSFetchedResultsController的委托设置为nil
将删除EXC\u BAD\u访问
错误
我正在使用ARC。很明显,这些物体正在被释放。这没关系。但为什么他们在发生变化时仍会得到通知
代码如下。我基本上是在数据库中跟踪web视图的历史记录
BookmarkViewController * bookmarkController = [[BookmarkViewController alloc] initWithStyle:UITableViewStylePlain andWebView:self.webView];
UINavigationController * bookmarkNavController = [[UINavigationController alloc] initWithRootViewController:bookmarkController];
self.bookmarkPopover = [[UIPopoverController alloc] initWithContentViewController:bookmarkNavController];
_bookmarkPopover.popoverContentSize = CGSizeMake(320, 44*10);
_bookmarkPopover.delegate = self;
bookmarkController.container=_bookmarkPopover;
bookmarkController.delegate=self;
BookmarkViewController
使用NSFetchedResultsController
,BookmarkViewController
是NSFetchedResultsController
的委托
- (NSFetchedResultsController *) myFetchedResultsController
{
if (self.fetchedResultsController != nil) {
return self.fetchedResultsController;
}
// Singleton
CoreDataManager * dataManager = [CoreDataManager defaultDataManager];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Bookmark" inManagedObjectContext:dataManager.managedObjectContext];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"label" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setEntity:entity];
[fetchRequest setPredicate:self.predicate];
[fetchRequest setSortDescriptors:sortDescriptors];
[fetchRequest setFetchBatchSize:20]; // Set the batch size to a suitable number.
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:dataManager.managedObjectContext
sectionNameKeyPath:@"type"
cacheName:nil];
self.fetchedResultsController.delegate = self;
return self.fetchedResultsController;
}
我还有:
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
[self.tableView beginUpdates];
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
[self.tableView endUpdates];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
BookmarkViewController * bookmarkViewController = [[BookmarkViewController alloc] initWithStyle:self.tableView.style
andWebView:self.webview
forFolder:bookmark.label];
[self.navigationController pushViewController:bookmarkViewController animated:YES];
}
我发现了一些相关的问题:
第二个链接让我想到了在dealoc方法中将委托设置为nil
-(void) dealloc
{
self.fetchedResultsController.delegate = nil;
}
但我使用的是ARC,因此无法显式调用[super dealloc]
。似乎可以解决问题,但我不确定这是否正确。我是否应该将其余局部变量设置为nil
?如果这覆盖了编译器生成的内容,它会泄漏吗?您不能显式调用[super dealloc]
,因为您不再需要这样做。这一切都由你来处理。您不需要清空剩余的属性,但可以使用-dealloc
清理使用此对象设置的任何观察者。