コアデータ挿入エラー

Question

食事と食べ物との関係が多すぎます（つまり、食事< < ------ >>食品）。食べ物は抽象クラスで、果物や野菜のいずれかになります。私は与えられた食事のすべての食品を表示するRootViewControllerを持っています。 1つのクラスでは野菜を追加し、もう1つはフルーツを追加します。

これらを食事に追加すると、次のエラーが発生します。私は実際に何が起こっているのか、これがどのように起こっているのかは分かりません。

Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-1912.3/UITableView.m:1046 

CoreData: error: Serious application error. An exception was caught from the delegate of NSFetchedResultsController during a call to -controllerDidChangeContent:. Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (2) must be equal to the number of rows contained in that section before the update (2), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out). with userInfo (null) 
2012-03-19 22:52:06.652 iGlucoTouch[682:11903] Meal Name: Meal #1 atIndex: 0 

RootViewController.h

@interface RootViewController : UIViewController <UITableViewDelegate, UITableViewDataSource, NSFetchedResultsControllerDelegate> 
{    
    NSFetchedResultsController *_fetchedResultsController; 
    NSManagedObjectContext *_context;  

    UITableView *_tableView; 
} 

@property (nonatomic, retain) NSFetchedResultsController *fetchedResultsController; 
@property (nonatomic, retain) NSManagedObjectContext *context; 
@property (nonatomic, retain) UITableView *tableView; 

@end 

RootViewController.m

@implementation RootViewController 

@synthesize fetchedResultsController = _fetchedResultsController; 
@synthesize context = _context; 
@synthesize tableView = _tableView; 


- (void)viewDidAppear:(BOOL)animated 
{ 
    self.tableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 0, 320, 400) style:UITableViewStyleGrouped]; 

    self.tableView.dataSource = self; 
    self.tableView.delegate = self; 
    self.tableView.rowHeight = 60.0; 

    [self.view addSubview:self.tableView]; 
    [self.tableView release]; 

    NSError *error; 
    if (![self.fetchedResultsController performFetch:&error]) { 
     NSLog(@"Unresolved error %@, %@", error, [error userInfo]); 
     exit(-1); 
    } 
} 

- (void)tableView:(UITableView *)tableView 
commitEditingStyle:(UITableViewCellEditingStyle)editingStyle 
forRowAtIndexPath:(NSIndexPath *)indexPath 
{  
    self.context = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 

    Food *food = [_fetchedResultsController objectAtIndexPath:indexPath]; 

    if (editingStyle == UITableViewCellEditingStyleDelete) { 

     [self.meal removeFoodsObject:food]; 

     NSError *error; 
     if (![self.context save:&error]) { 
      NSLog(@"Unresolved error %@, %@", error, [error userInfo]); 
      exit(-1); 
     } 
    } 
} 


- (void)tableView:(UITableView *)tableView 
commitEditingStyle:(UITableViewCellEditingStyle)editingStyle 
forRowAtIndexPath:(NSIndexPath *)indexPath 
{  
    self.context = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 

    Food *food = [_fetchedResultsController objectAtIndexPath:indexPath]; 

    if (editingStyle == UITableViewCellEditingStyleDelete) { 

     [self.meal removeFoodsObject:food]; 

     NSError *error; 
     if (![self.context save:&error]) { 
      NSLog(@"Unresolved error %@, %@", error, [error userInfo]); 
      exit(-1); 
     } 
    } 
} 

- (NSFetchedResultsController *)fetchedResultsController 
{  
    self.context = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 

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

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; 
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Food" inManagedObjectContext:self.context]; 
    [fetchRequest setEntity:entity]; 

    NSPredicate *foodPredicate = [NSPredicate predicateWithFormat:@"ANY meals == %@", self.meal]; 
    [fetchRequest setPredicate:foodPredicate]; 

    NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES]; 
    [fetchRequest setSortDescriptors:[NSArray arrayWithObject:sort]];  

    [fetchRequest setFetchBatchSize:20]; 

    NSFetchedResultsController *theFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.context sectionNameKeyPath:nil cacheName:nil]; 

    self.fetchedResultsController = theFetchedResultsController; 
    _fetchedResultsController.delegate = self; 

    [sort release]; 
    [fetchRequest release]; 
    [theFetchedResultsController release]; 

    return _fetchedResultsController; 
} 

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

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

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

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

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

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

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

私は別のクラスでは、このように果物や野菜を追加します。

は

self.context = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 

Fruit *fruit = [_fetchedResultsController objectAtIndexPath:indexPath]; 

[self.meal addFoodsObject:fruit]; 

NSError *error; 
if (![self.context save:&error]) { 
    NSLog(@"Error: %@", [error localizedDescription]); 
} 

Answer 1

どうやら私はfetchedResultsControllerとコンテキストをnilに設定していませんでした。私はdeallocにいましたが、これはアプリケーションデリゲートで宣言されたタブバーのビューの1つだったので、呼び出されませんでした。そこで以下のコードを追加しました。私は文脈を共有しているからかもしれない。

- (void)viewDidDisappear:(BOOL)animated 
{ 
    self.fetchedResultsController = nil; 
    self.context = nil; 
} 

Answer 2

はい - のように聞こえますあなたは新しい電子を加えなかったNSFetchResultsControllerがサポートしているNSArrayにntryしてください。あなたが[self.meal addFoodsObject:fruit]を行う直後に、あなたも自分

[self.tableView insertRowsAtIndexPaths: [NSArray arrayWithObject:newIndexPath] 
            withRowAnimation: UITableViewRowAnimationRight]; 

ような何かを呼び出すことができるはずです。 Jeff LaMarcheのリンクは大きな説明です。