ID 为 [...] 的 NSManagedObject 已失效

Question

我正在使用核心数据构建一个应用程序。我的 RootViewController 由 appDelegate 加载，大部分来自模板。不过，我已将实体名称更改为“Clocks”并添加了一堆行。

我的 RootViewController 提供了一个具有 UINavigationController 的 MVC。当我将数据保存到数据库时，UINavigationController 类使用 [[UIApplication sharedApplication]delegate] 保存数据，以访问实际执行保存操作的 appDelegate。 编辑数据的方式相同，但它不是调用应用程序委托中的插入函数，而是调用更新函数。

现在，一切都很顺利……实际上非常完美。但是......几次后，打开编辑并保存在视图中，我的应用程序崩溃了。它在模拟器和我的 iPhone 4 上都执行此操作。这是我的意思的示例（电影）： http://dl.dropbox.com/u/3077127/has_been_invalidated.mov

这是我的 RootViewController.m 的代码：

#import "RootViewController.h"
#import "RootViewControllerClockCell.h"
#import "RootViewControllerClockCellFooter.h"
#import "configuration.h"
#import "AddClockViewController.h"
#import "clockAppDelegate.h"

#import "AddClockNavigationController.h"

@interface RootViewController ()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
@end


@implementation RootViewController

@synthesize fetchedResultsController=fetchedResultsController_, managedObjectContext=managedObjectContext_;


#pragma mark -
#pragma mark View lifecycle

- (void)viewDidLoad {
    [super viewDidLoad];

    [self setTitle:NSLocalizedString(@"Alarms", @"AddClockNavigationController")];

    // Set up the edit and add buttons.
    self.navigationItem.leftBarButtonItem = self.editButtonItem;

    UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showAddAlarmView)];
    self.navigationItem.rightBarButtonItem = addButton;
    [addButton release];

    [self.tableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
    [self.tableView setBackgroundColor:[UIColor clearColor]];
    [self.tableView setBackgroundView:[[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"clockTableBackground"]] autorelease]];
    [self.tableView setAllowsSelectionDuringEditing:YES];

    if (managedObjectContext_ == nil) 
    { 
        managedObjectContext_ = [(ClockAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        NSLog(@"After managedObjectContext: %@",  managedObjectContext_);
    }

    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate=self;
    locationManager.desiredAccuracy=kCLLocationAccuracyBest;

    [locationManager startUpdatingLocation];
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {

    location = newLocation.coordinate;
    [locationManager stopUpdatingLocation];

    [self.tableView reloadData];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [locationManager stopUpdatingLocation];

    [super viewWillDisappear:animated];
}


// Implement viewWillAppear: to do additional setup before the view is presented.
- (void)viewWillAppear:(BOOL)animated {
    [locationManager startUpdatingLocation];

    [super viewWillAppear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    if ([Configuration isIpad])
    {
        return YES;
    }
    else {
        return (interfaceOrientation == UIInterfaceOrientationPortrait);
    }
}

- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {

    // @TODO
    // Remove unused function
}

- (void)showAddAlarmView
{
    AddClockNavigationController *viewController = [[AddClockNavigationController alloc] initWithNibName:@"AddClockNavigationController" bundle:nil];

    [[self navigationController] presentModalViewController:viewController animated:YES];
    [viewController release];
}

#pragma mark -
#pragma mark Add a new object

- (void)setEditing:(BOOL)editing animated:(BOOL)animated
{
    [super setEditing:(BOOL)editing animated:(BOOL)animated];
    self.navigationItem.rightBarButtonItem.enabled = !editing;
}

#pragma mark -
#pragma mark Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return [[self.fetchedResultsController sections] count];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];

    int retValue = [sectionInfo numberOfObjects];

    retValue++;

    return retValue;
}

// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:indexPath.section];

    if (indexPath.row < [sectionInfo numberOfObjects])
    {
        static NSString *CellIdentifier = @"RootViewControllerClockCell";
        RootViewControllerClockCell *cell = (RootViewControllerClockCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];

        if (cell == nil){
            NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"RootViewControllerClockCell" owner:nil options:nil];

            for(id currentObject in topLevelObjects)
            {
                if([currentObject isKindOfClass:[RootViewControllerClockCell class]])
                {
                    cell = (RootViewControllerClockCell *)currentObject;
                    break;
                }
            }
        }

        // Configure the cell.
        NSManagedObject *managedObject = [[self.fetchedResultsController objectAtIndexPath:indexPath] retain];

        [[cell titleText] setText:[[managedObject valueForKey:@"title"] description]];

        UISwitch *mySwitch = [[[UISwitch alloc] initWithFrame:CGRectZero] autorelease];
        [cell addSubview:mySwitch];
        cell.accessoryView = mySwitch;
        [cell setSelectionStyle:UITableViewCellSelectionStyleNone];

        [mySwitch setTag:indexPath.row];

        BOOL isOn = [(NSNumber*)[managedObject valueForKey:@"active"] boolValue];

        [(UISwitch *)cell.accessoryView setOn:isOn];
        [(UISwitch *)cell.accessoryView addTarget:self action:@selector(setClockEnabled:) forControlEvents:UIControlEventValueChanged];

        [cell setEditingAccessoryType:UITableViewCellAccessoryDisclosureIndicator];

        [currentLocation release];
        [cellLocation release];
        [managedObject release];

        return cell;
    }
    else {
        static NSString *CellIdentifier = @"RootViewControllerClockCellFooter";
        RootViewControllerClockCellFooter *cell = (RootViewControllerClockCellFooter*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];

        if (cell == nil){
            NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"RootViewControllerClockCellFooter" owner:nil options:nil];

            for(id currentObject in topLevelObjects)
            {
                if([currentObject isKindOfClass:[RootViewControllerClockCellFooter class]])
                {
                    cell = (RootViewControllerClockCellFooter *)currentObject;
                    break;
                }
            }
        }

        return cell;
    }
}

- (NSString*)distanceToString:(double)distance
{
    NSString *returnString = @"";

    if (distance < 1000)
    {
        returnString = [NSString stringWithFormat:@"%gm", round(distance)];
    }
    else {
        returnString = [NSString stringWithFormat:@"%gkm", round(distance/1000)];
    }

    return returnString;
}

- (void)setClockEnabled:(UISwitch*)sender
{
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:sender.tag inSection:0];

    NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
    [managedObject setValue:[NSNumber numberWithBool:sender.on] forKey:@"active"];

    NSError *error = nil;
    if (![fetchedResultsController_ performFetch:&error]) {
        /*
         Replace this implementation with code to handle the error appropriately.

         abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
         */
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }
}

// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:indexPath.section];

    if ((indexPath.row > [sectionInfo numberOfObjects]-1) || [self.tableView numberOfRowsInSection:indexPath.section] == 1)
        return NO;
    else
        return YES;
}

// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        // Delete the managed object for the given index path
        NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
        [context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];

        // Save the context.
        NSError *error = nil;
        if (![context save:&error]) {
            /*
             Replace this implementation with code to handle the error appropriately.

             abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
             */
            NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
            abort();
        }

        if ([self.tableView numberOfRowsInSection:0] == 1)
        {
            [self.tableView reloadData];
        }
    }
}

- (void)updateAlarm:(NSManagedObject*)originalAlarm withAlarm:(NSManagedObject*)newAlarm
{
    NSLog(@"Update!");

    NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
    [context deleteObject:originalAlarm];
    [context insertObject:newAlarm];

    // Save the context.
    NSError *error = nil;
    if (![context save:&error]) {
        /*
         Replace this implementation with code to handle the error appropriately.

         abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
         */
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }
}

- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
    // The table view should not be re-orderable.
    return NO;
}


#pragma mark -
#pragma mark Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"Did select row");

    if ([self.tableView isEditing])
    {
        // Show editing mode
        NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];

        AddClockNavigationController *viewController = [[AddClockNavigationController alloc] initWithNibName:@"AddClockNavigationController" bundle:nil editManagedObject:managedObject];       
        [[self navigationController] presentModalViewController:viewController animated:YES];
        [viewController release];
    }
}

- (void)cancelAddAlarmView
{
    [self.modalViewController dismissModalViewControllerAnimated:YES];
}

#pragma mark -
#pragma mark Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController {

    if (fetchedResultsController_ != nil) {
        return fetchedResultsController_;
    }

    /*
     Set up the fetched results controller.
     */
    // Create the fetch request for the entity.
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    // Edit the entity name as appropriate.
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Clocks" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];

    // Set the batch size to a suitable number.
    [fetchRequest setFetchBatchSize:20];

    // Edit the sort key as appropriate.
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"addDate" ascending:NO];
    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

    [fetchRequest setSortDescriptors:sortDescriptors];

    // Edit the section name key path and cache name if appropriate.
    // nil for section name key path means "no sections".
    NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:@"Root"];
    aFetchedResultsController.delegate = self;
    self.fetchedResultsController = aFetchedResultsController;

    [aFetchedResultsController release];
    [fetchRequest release];
    [sortDescriptor release];
    [sortDescriptors release];

    NSError *error = nil;
    if (![fetchedResultsController_ performFetch:&error]) {
        /*
         Replace this implementation with code to handle the error appropriately.

         abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
         */
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }

    return fetchedResultsController_;
}    


#pragma mark -
#pragma mark Fetched results controller delegate


- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView beginUpdates];
}


- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {

    switch(type) {
        case NSFetchedResultsChangeInsert:
            [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}


- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
       atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
      newIndexPath:(NSIndexPath *)newIndexPath {

    UITableView *tableView = self.tableView;

    switch(type) {

        case NSFetchedResultsChangeInsert:
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeUpdate:
            [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
            break;

        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
            [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}


- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
    [self.tableView endUpdates];
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:indexPath.section];

    if (indexPath.row < [sectionInfo numberOfObjects])
    {
        return 92;
    }
    else {
        return 40;
    }
}


/*
 // Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed. 

 - (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
 // In the simplest, most efficient, case, reload the table view.
 [self.tableView reloadData];
 }
 */


#pragma mark -
#pragma mark Memory management

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Relinquish ownership any cached data, images, etc that aren't in use.
}


- (void)viewDidUnload {
    // Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
    // For example: self.myOutlet = nil;
}

- (void)dealloc {
    [fetchedResultsController_ release];
    [managedObjectContext_ release];

    [locationManager stopUpdatingLocation];
    [locationManager release];

    [super dealloc];
}


@end

编辑
这是保存按钮的代码，AddClockNavigationController.m：

- (IBAction)saveAlarm
{
    [self saveTheAlarm];
}

- (void)saveTheAlarm
{
    AddClockViewController *viewController = [navigationController.viewControllers objectAtIndex:0];

    UITableView *alarmTable = viewController.theTable;

    NSIndexPath *textFieldIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
    UITextField *textField = (UITextField*)[[alarmTable cellForRowAtIndexPath:textFieldIndexPath] accessoryView];

    ClockAppDelegate *appDelegate = (ClockAppDelegate*)[[UIApplication sharedApplication] delegate];

    RootViewController *parentView = [[RootViewController alloc] init];
    [appDelegate addNewAlarmWithTitle:textField.text sound:@"" recurring:[viewController hasRecurring] recurringDays:viewController.recurringDictionary];

    [parentView.tableView reloadData];
    [self.parentViewController dismissModalViewControllerAnimated:YES];

    [parentView release];
}

ClockAppDelegate.m

- (void)addNewAlarmWithTitle:(NSString*)alarmTitle sound:(NSString*)sound recurring:(BOOL)isRecurring recurringDays:(NSDictionary*)days
{
    NSManagedObjectContext *context = managedObjectContext_;
    NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:@"Clocks" inManagedObjectContext:context];

    [newManagedObject setValue:alarmTitle forKey:@"title"];
    [newManagedObject setValue:sound forKey:@"alarm"];
    [newManagedObject setValue:[NSNumber numberWithBool:TRUE] forKey:@"active"];
    [newManagedObject setValue:[[NSDate alloc] init] forKey:@"addDate"];

    [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:isRecurring] forKey:@"recurring"];

    NSArray *myKeys = [days allKeys];
    NSArray *sortedKeys = [myKeys sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];

    for (id key in sortedKeys) {
        if ([(NSString*)[days objectForKey:key] isEqualToString:@"1"])
        {
            if ([key isEqualToString:@"0"])
            {
                [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"mon"];
            }
            else if ([key isEqualToString:@"1"])
            {
                [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"tue"];
            }
            else if ([key isEqualToString:@"2"])
            {
                [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"wed"];
            }
            else if ([key isEqualToString:@"3"])
            {
                [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"thu"];
            }
            else if ([key isEqualToString:@"4"])
            {
                [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"fri"];
            }
            else if ([key isEqualToString:@"5"])
            {
                [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"sat"];
            }
            else if ([key isEqualToString:@"6"])
            {
                [newManagedObject setPrimitiveValue:[NSNumber numberWithBool:TRUE] forKey:@"sun"];
            }
        }
    }

    // Save the context.
    NSError *error = nil;
    if (![context save:&error]) {
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }
}

我做错了什么？

谨致问候，
保罗·皮伦

Answer 1

来自核心数据文档

托管对象无效问题：
您会看到一个异常，看起来
与此示例类似：

[_assignObject:toPersistentStore:]:
ID 为 #### 的 NSManagedObject 有
已被宣告无效。原因：要么你
因故障已删除该商店
你正试图开火，或者
托管对象的上下文已发送
重置消息。

补救措施：你应该放弃这个
目的。如果您再次添加商店，
您可以尝试再次获取该对象

因此，基本上，您拥有对已与其存储或上下文断开连接的托管对象的引用。

我没有看到发生这种情况的明显地方，但您正在向 tableView:cellForRowAtIndexPath: 中的托管对象发送一条保留消息：

NSManagedObject *managedObject = [[self.fetchedResultsController objectAtIndexPath:indexPath] retain];

...即使您随后释放它，这也是危险的。永远不要保留托管对象，而是依赖上下文来保留它。否则，上下文可能会释放托管对象并将其标记为无效，而另一个对象则使其保持活动状态。

我建议检查所有代码并找到将保留发送到托管对象的所有位置，并删除不必要的保留/释放代码。这可能会解决问题。

如果没有，您需要检查您的持久存储是否已正确分配给持久存储协调器。

Answer 2

我遇到了这个问题，并且我已经通过评论 RESET for Managed Object context 下面的苹果文档中的这个问题的描述来独奏：

您可以使用 NSManagedObjectContext 的重置方法来删除与上下文关联的所有托管对象并“重新开始”，就像您一样刚刚创建了它。请注意，与该上下文关联的任何托管对象都将失效，因此您需要放弃对您仍然感兴趣的该上下文关联的任何引用并重新获取与该上下文关联的任何对象。