ios – 刷新NSFetchedResultsController数据？

@H_301_2@我没有编辑表视图.

@H_301_2@我无法掌握我做错了什么如果我关闭应用程序并重新启动,我的新对象在表视图中.我正在尝试调用reloadData,当我收到一个新的对象的通知,并且我也尝试再次执行提取,但我最终得到的是一个空的表视图.

@interface MyNotesViewController : UIViewController
{
    NsmanagedObjectContext * __managedObjectContext;
    UITableView * _notesTableView;
    MyNotesTableViewDelegate_Datasource * _tableDelegate_Datasource;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    _tableDelegate_Datasource = [[MyNotesTableViewDelegate_Datasource alloc] init];
    _tableDelegate_Datasource.managedObjectContext = __managedObjectContext;
    [_notesTableView setDatasource:_tableDelegate_Datasource];

    NSError * _coreDataError;
    BOOL success = [[_tableDelegate_Datasource fetchedResultsController] performFetch:&_coreDataError];

    if(success){
        [_notesTableView reloadData];
    }
}

@interface MyCommutesTableViewDelegate_Datasource : NSObject 

<UITableViewDatasource,NSFetchedResultsControllerDelegate>
{
    NsmanagedObjectContext * __managedObjectContext;
    NSFetchedResultsController * __fetchedResultsController;
}

@property (nonatomic,retain) NsmanagedObjectContext *managedObjectContext;

@end

-(NSFetchedResultsController*)fetchedResultsController{
    if(!__fetchedResultsController){
        NSFetchrequest * request = [[NSFetchrequest alloc] init];
        [request setEntity:[NSEntityDescription entityForName:@"Note" inManagedObjectContext:__managedObjectContext]];

        [request setFetchBatchSize:10];

        NSSortDescriptor * sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"noteDate" ascending:NO];
        [request setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]];
        [sortDescriptor release];

        __fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchrequest:request managedObjectContext:__managedObjectContext sectionNameKeyPath:nil cachename:nil];


        __fetchedResultsController.delegate = self;
        [request release];

    }
    return __fetchedResultsController;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    id <NSFetchedResultsSectionInfo> sectionInfo = 
    [[__fetchedResultsController sections] objectATindex:section];
    return [sectionInfo numberOfObjects];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowATindexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"NotesTableViewCell";

    NotesTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {        
        NSArray * topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"NotesTableViewCell" owner:nil options:nil];
        for(id currentObject in topLevelObjects){
            if([currentObject isKindOfClass:[UITableViewCell class]]){
                cell = (NotesTableViewCell*) currentObject;
                break;
            }
        }

    }

// Configure the cell.
    Note * _note = [__fetchedResultsController objectATindexPath:indexPath];

    [...]

    return cell;
}

@H_301_2@所以我想没有问题,我如何实现NSFetchResultsController.但是,在保存新对象后,请求如何开始不返回结果？

@H_301_2@标准要求：

-(NSArray*)getNotes{
    NSFetchrequest * request = [[NSFetchrequest alloc] init];

    NSEntityDescription * entity = [NSEntityDescription entityForName:@"Note" inManagedObjectContext:[self managedObjectContext]];
    [request setEntity:entity];

    NSSortDescriptor * sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"noteDate" ascending:NO];
    [request setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]];
    [sortDescriptor release];

    NSError * coreDataError;
    NSArray * fetchedObjects = [[self managedObjectContext] executeFetchrequest:request error:&coreDataError];
    [request release];

    if(fetchedObjects != nil){
        return fetchedObjects;
    } else {
        NSLog(@"ERR: %@",coreDataError);
        return nil;
    }
}

@H_801_29@

解决方法

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