Objective C- NSManagedObjectContext和NSFetchedResultsController发布处理

Question

我需要一些关于使用NSManagedObjectContext对象进行内存管理的信息。我在ipad-App上编程，我使用的是核心数据对象。

我的UIApplicationDelegate控制NSManagedObjectContext：

- (NSManagedObjectContext *)managedObjectContext {
if (__managedObjectContext != nil)
{
    return __managedObjectContext;
}

NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil)
{
    __managedObjectContext = [[NSManagedObjectContext alloc] init];
    [__managedObjectContext setPersistentStoreCoordinator:coordinator];
}
return __managedObjectContext;
}

我正在使用ManagedObjectContext的实例来显示核心数据对象。就像这样。示例表视图控制器：

CRMAppDelegate *appDelegate = (CRMAppDelegate*) [[UIApplication sharedApplication] delegate];
self.managedObjectContext = appDelegate.managedObjectContext;

// Initialize NSFetchedResultsController to retrieve data from the database.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setEntity:[NSEntityDescription entityForName:@"Contact" inManagedObjectContext:self.managedObjectContext]];

// Sort results ascending by last name, first name.
NSSortDescriptor *sortDescriptorFirstLetterLastName = [[NSSortDescriptor alloc] initWithKey:@"firstLetterOfLastName" ascending:YES];
NSSortDescriptor *sortDescriptorLastName = [[NSSortDescriptor alloc] initWithKey:@"name_last" ascending:YES];
NSSortDescriptor *sortDescriptorFirstName = [[NSSortDescriptor alloc] initWithKey:@"name_first" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptorFirstLetterLastName, sortDescriptorLastName, sortDescriptorFirstName, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
[sortDescriptors release];
[sortDescriptorFirstLetterLastName release];
[sortDescriptorFirstName release];
[sortDescriptorLastName release];

/*
if ([self.managedObjectContext countForFetchRequest:fetchRequest error:NULL] == 0) {
    [self reloadContactData];
}
 */

// Create NSFetched Results controller instance.
fetchedResultsController = [[NSFetchedResultsController alloc]
                            initWithFetchRequest:fetchRequest
                            managedObjectContext:self.managedObjectContext
                            sectionNameKeyPath:@"firstLetterOfLastName"
                            cacheName:@"ContactsViewCache"];
[fetchRequest release];
self.fetchedResultsController.delegate = self;

// Load data.
NSError *error;
if (![fetchedResultsController performFetch:&error]) {
    // Update to handle the error appropriately.
    NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}

可以像这样实例化NSManagedObjectContext吗？因为，在我测试我的应用程序时，上下文的retainCount会一直增加到第10天，即使我在"viewDidUnload“和"dealloc”中释放了上下文。

我尝试过将上下文保留在处理程序类中，如下所示：

- (NSManagedObjectContext *)getManagedObjectContext
{
NSManagedObjectContext *context = [self.managedObjectContext autorelease];

return context;
}

与NSManagedObjectContext对象和实例交互的最佳方式是什么？Thx和sry回答我的愚蠢的问题:)

Answer 1

retainCount返回的值是无意义的。别费心看它了。

使用泄漏工具或heapshot analysis来确定您的应用程序是否正在泄漏。