【问题标题】:Getting an NSInvalidArguementException error收到 NSInvalidArguementException 错误
【发布时间】:2011-04-28 08:05:43
【问题描述】:

我认为这可能与过度释放有关?它总是在if (![managedObjectContext save:&error]) 崩溃,就像每三次调用该方法一样(当我添加 3 个练习时)。

更新:我注意到当我往返于不同的例程实例时会发生这种情况。

2011-04-28 04:02:58.160 Curl[8035:707] Serious application error.  Exception was caught during Core Data change processing.  This is usually a bug within an observer of NSManagedObjectContextObjectsDidChangeNotification.  -[__NSCFDictionary controllerWillChangeContent:]: unrecognized selector sent to instance 0x1ba1b0 with userInfo (null)
    2011-04-28 04:02:58.353 Curl[8035:707] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary controllerWillChangeContent:]: unrecognized selector sent to instance 0x1ba1b0'

方法

-(void)addExercise
{   
    if (managedObjectContext == nil) 
    { 
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        [managedObjectContext retain];
    }

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

    NSError *error = nil;

    Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];

    exercise.name = selectedExercise;

    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);

    [theSelectedRoutine addRoutineToExercisesObject:exercise];

    if (![managedObjectContext save:&error]) 
    {
        // Handle the error.
    }
    NSLog(@"%@", error);
    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);
    [self.routineTableView reloadData];

}

这里是完整的代码:

@implementation RoutineDayTableViewController

@synthesize fetchedResultsController;
@synthesize exerciseChooserView;
@synthesize routineTableView;
@synthesize managedObjectContext;
@synthesize selectedExercise;
@synthesize entityArray;
@synthesize theSelectedRoutine;

- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)dealloc
{
    NSLog(@"dealloc");
    [fetchedResultsController release];
    [selectedExercise release];
    [managedObjectContext release];
    [exerciseChooserView release];
    [routineTableView release];
    [entityArray release];
    [theSelectedRoutine release];
    [super dealloc];
}

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

    // Release any cached data, imagtaes, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];

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

    if (managedObjectContext == nil) 
    { 
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        [managedObjectContext retain];
    }
    [self loadData];
}

-(void)loadData
{
    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:managedObjectContext];
    [request setEntity:entity];

    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];

    NSManagedObject *selectedObject = [entityArray objectAtIndex:indexPath.row];

    NSLog(@"After managedObjectContext: %@",  managedObjectContext);

    NSError *error = nil;
    NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
    if (mutableFetchResults == nil) {
        // Handle the error.
    }
    self.entityArray = mutableFetchResults;

    [request setPredicate: [NSPredicate predicateWithFormat: @"routineExercises = %@", selectedObject]];    

    [mutableFetchResults release];
    [request release];
}

- (void)viewDidUnload
{
    NSLog(@"viewDidUnload");
    [super viewDidUnload];
    self.exerciseChooserView = nil;
    self.routineTableView = nil;
    self.fetchedResultsController = nil;

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

#pragma mark - Exercise Editing

-(IBAction)exerciseChooser
{
    RoutineExerciseChooserViewController *routineExerciseChooserViewController = [[[RoutineExerciseChooserViewController alloc] init] autorelease];
    [self.navigationController pushViewController:routineExerciseChooserViewController animated:YES];
}

-(void)addExercise
{   
    if (managedObjectContext == nil) 
    { 
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        [managedObjectContext retain];
    }

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

    NSError *error = nil;

    Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];

    exercise.name = selectedExercise;

    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);

    [theSelectedRoutine addRoutineToExercisesObject:exercise];

    if (![managedObjectContext save:&error]) 
    {
        // Handle the error.
    }
    NSLog(@"%@", error);
    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);
    //[self.routineTableView reloadData];
}

-(void)toggleEdit
{
    [self.routineTableView setEditing: !self.routineTableView.editing animated:YES];

    if (self.routineTableView.editing)
        [self.navigationItem.rightBarButtonItem setTitle:@"Cancel"];
    else
        [self.navigationItem.rightBarButtonItem setTitle:@"Edit"];
}

#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];
    return [sectionInfo numberOfObjects];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [routineTableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    Exercise *tempExercise = (Exercise *)[fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text = tempExercise.name;

    return cell;
}

-(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]];
        NSLog(@"fetched results : \n%@\n",[self.fetchedResultsController fetchedObjects]);

        // Commit the change.
        NSError *error = nil;

        // Update the array and table view.
        if (![managedObjectContext save:&error]) 
        {
            // Handle the error.
        }
        //[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
    }
}

- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
    NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text = [[managedObject valueForKey:@"name"] description];
}

#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Navigation logic may go here. Create and push another view controller.
    [routineTableView deselectRowAtIndexPath:indexPath animated:YES];

     DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
     // ...
     // Pass the selected object to the new view controller.
     [self.navigationController pushViewController:detailViewController animated:YES];
     [detailViewController release];
}

#pragma mark - Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController
{
    if (fetchedResultsController != nil)
    {
        return fetchedResultsController;
    }

    // Create the fetch request for the entity.
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    // Edit the entity name as appropriate.
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];
    NSLog(@"fetchedResultsController theSelectedRoutine: %@",theSelectedRoutine);
    [fetchRequest setPredicate:[NSPredicate predicateWithFormat: @"ANY exerciseToRoutine == %@", theSelectedRoutine]];

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

    // Edit the sort key as appropriate.
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" 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:nil];
    aFetchedResultsController.delegate = self;
    self.fetchedResultsController = aFetchedResultsController;

    NSError *error = nil;
    if (![self.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;

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

#pragma mark - Fetched results controller delegate

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

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
    switch(type)
    {
        case NSFetchedResultsChangeInsert:
            [self.routineTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [self.routineTableView 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.routineTableView;

    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.routineTableView endUpdates];
}
@end

更新 - 这是新的更新代码:

@implementation RoutineDayTableViewController

@synthesize fetchedResultsController;
@synthesize exerciseChooserView;
@synthesize routineTableView;
@synthesize managedObjectContext;
@synthesize selectedExercise;
@synthesize theSelectedRoutine;

- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)dealloc
{
    NSLog(@"dealloc");
    [fetchedResultsController release];
    [selectedExercise release];
    [managedObjectContext release];
    [exerciseChooserView release];
    [routineTableView release];
    [theSelectedRoutine release];
    [super dealloc];
}

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

    // Release any cached data, imagtaes, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];

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

    if (managedObjectContext == nil) 
    { 
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        [managedObjectContext retain];
    }
}

- (void)viewDidUnload
{
    NSLog(@"viewDidUnload");
    [super viewDidUnload];
    self.exerciseChooserView = nil;
    self.routineTableView = nil;
    self.fetchedResultsController = nil;

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

#pragma mark - Exercise Editing

-(IBAction)exerciseChooser
{
    RoutineExerciseChooserViewController *routineExerciseChooserViewController = [[[RoutineExerciseChooserViewController alloc] init] autorelease];
    [self.navigationController pushViewController:routineExerciseChooserViewController animated:YES];
}

-(void)addExercise
{   
    if (managedObjectContext == nil) 
    { 
        managedObjectContext = [(CurlAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
        [managedObjectContext retain];
    }

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

    NSError *error = nil;

    Exercise *exercise = (Exercise *)[NSEntityDescription insertNewObjectForEntityForName:@"Exercise" inManagedObjectContext:managedObjectContext];

    exercise.name = self.selectedExercise;

    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);

    [theSelectedRoutine addRoutineToExercisesObject:exercise];

    if (![fetchedResultsController.managedObjectContext save:&error]) 
    {
        // Handle the error.
    }
    NSLog(@"%@", error);
    NSLog(@"addExercise theSelectedRoutine:  %@", theSelectedRoutine);
    //[self.routineTableView reloadData];
    [exercise release];
    [error release];
}

-(void)toggleEdit
{
    [self.routineTableView setEditing: !self.routineTableView.editing animated:YES];

    if (self.routineTableView.editing)
        [self.navigationItem.rightBarButtonItem setTitle:@"Cancel"];
    else
        [self.navigationItem.rightBarButtonItem setTitle:@"Edit"];
}

#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];
    return [sectionInfo numberOfObjects];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [routineTableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    Exercise *tempExercise = (Exercise *)[fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text = tempExercise.name;

    return cell;
}

-(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]];
        NSLog(@"fetched results : \n%@\n",[self.fetchedResultsController fetchedObjects]);

        // Commit the change.
        NSError *error = nil;

        // Update the array and table view.
        if (![fetchedResultsController.managedObjectContext save:&error]) 
        {
            // Handle the error.
        }
        //[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
    }
}

- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
    NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
    cell.textLabel.text = [[managedObject valueForKey:@"name"] description];
}

#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Navigation logic may go here. Create and push another view controller.
    [routineTableView deselectRowAtIndexPath:indexPath animated:YES];

     DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
     // ...
     // Pass the selected object to the new view controller.
     [self.navigationController pushViewController:detailViewController animated:YES];
     [detailViewController release];
}

#pragma mark - Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController
{
    if (fetchedResultsController != nil)
    {
        return fetchedResultsController;
    }

    // Create the fetch request for the entity.
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    // Edit the entity name as appropriate.
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Exercise" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];
    NSLog(@"fetchedResultsController theSelectedRoutine: %@",theSelectedRoutine);
    [fetchRequest setPredicate:[NSPredicate predicateWithFormat: @"ANY exerciseToRoutine == %@", theSelectedRoutine]];

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

    // Edit the sort key as appropriate.
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" 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:nil];
    aFetchedResultsController.delegate = self;
    self.fetchedResultsController = aFetchedResultsController;

    NSError *error = nil;
    if (![self.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();
    }

    [aFetchedResultsController release];
    [fetchRequest release];
    [sortDescriptor release];
    [sortDescriptors release];
    return fetchedResultsController;
}    

#pragma mark - Fetched results controller delegate

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

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
    switch(type)
    {
        case NSFetchedResultsChangeInsert:
            [self.routineTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [self.routineTableView 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.routineTableView;

    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.routineTableView endUpdates];
}
@end

【问题讨论】:

    标签: iphone objective-c core-data


    【解决方案1】:

    您混合了两种完全独立的访问核心数据信息的方法。对于每个 tableview,您应该只有一个上下文引用和一个 fetch。您至少有两个同时操作的提取和两个上下文引用。你需要选择一个或另一个。如果您使用的是获取结果控制器,那么您不需要viewDidLoadloadData 中的代码。

    在引用属性时,您还需要使用 self 引用,例如您需要使用self.selectedExercise 而不仅仅是selectedExercise。只有self 参考表为您提供自动保留和释放。

    【讨论】:

    • 感谢 TechZen,我已经删除了 loadData 和变量 entityArray 的方法。我将 self 添加到此行以生成 exercise.name = self.selectedExercise;。还有什么我错过的吗?
    • 乍一看,看起来好多了。当您从 fetch 返回托管对象时,我建议您使用强制转换,例如` 练习 *tempExercise = (Exercise *)[fetche...` 你不能总是确定你会得到什么类(尤其是在更复杂的数据模型中),并且强制转换强制运行时尝试将其视为强制转换班级。这可能会导致细微的错误。
    • 感谢 TechZen。我知道演员表是什么,但我在(Exercise*) 之后要添加什么,会不会是Exercise *tempExercise = (Exercise *)[FetchedResultsController alloc]init]; 之类的东西?
    • 另外,我仍然遇到一些有趣的崩溃。如果这个类现在看起来没问题,那么问题可能出在它的父 tableview,Routine。如果你愿意看看是否有什么让你觉得奇怪的话,我已经把这门课贴在这里了。谢谢! stackoverflow.com/questions/5824139/…
    • 要删除演员表,只需从行中删除(Exercise *)
    【解决方案2】:

    我发现您的代码存在一些问题。

    • 最有可能导致错误的是fetchedResultsController 方法泄漏了对NSFetchedResultsController 的引用以及一些其他对象。释放必须发生在退货之前,而不是之后。
    • 为什么loadData在使用后会在请求中添加谓词?
    • loadData 的意义何在?它设置了entityArray,它似乎没有在其他任何地方使用。你添加fetchedResultsController之前留下的?
    • tableView:commitEditingStyle:forRowAtIndexPath:fetchedResultsController.managedObjectContext 中删除一个对象,但随后保存self.managedObjectContext。这应该可行,因为它们应该始终相同,但对两个操作使用相同的对象在语义上会更正确。

    【讨论】:

    • 感谢 Anomie,所以我删除了 loadData 方法并删除了 entityArray。您在此方法中引用的泄漏还是在其余方法中引用的泄漏 - (NSFetchedResultsController *)fetchedResultsController method?我将commitEditingStyle 代码切换为if (![fetchedResultsController.managedObjectContext save:&amp;error])。但是,在添加了一些练习并在例程之间切换后,我仍然让应用程序崩溃。
    • 我第三次在例程之间切换时会崩溃。日志显示[CALayer controllerWillChangeContent:]: unrecognized selector sent to instance 0x5d4bd00Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[CALayer controllerWillChangeContent:]: unrecognized selector sent to instance 0x5d4bd00'
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