7
我使用的輸出tableView
的標準實現。在-viewDidLoad
末我在做第一個電話:fetchedResultsController.fetchedObjects.count = 0,但它充滿了對象
NSError *error = nil;
if (![[self fetchedResultsController] performFetch:&error])
{
NSLog(@"Error! %@",error);
abort();
}
這是我fetchedResultsController:
- (NSFetchedResultsController *) fetchedResultsController
{
if (_fetchedResultsController != nil)
{
return _fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Preparation"
inManagedObjectContext:_context];
[fetchRequest setEntity:entity];
int i = 1;
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"ismer == %d", i];
fetchRequest.predicate = predicate;
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects: sortDescriptor, nil];
fetchRequest.sortDescriptors = sortDescriptors;
_fetchedResultsController = [[NSFetchedResultsController alloc]initWithFetchRequest:fetchRequest managedObjectContext:_context sectionNameKeyPath:nil cacheName:nil];
_fetchedResultsController.delegate = self;
NSLog(@"_fetchedResultsController.fetchedObjects.count - %d", _fetchedResultsController.fetchedObjects.count);
return _fetchedResultsController;
}
我tableView
方法:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections]count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> secInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
return [secInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
CDPreparation *drug = (CDPreparation *)[self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [NSString stringWithFormat:@"%@", drug.name];
return cell;
}
所以,問題是:
日誌中的_fetchedResultsController.fetchedObjects.count
等於0,但視覺tableView
充滿了對象。爲什麼我有兩個不同的計數結果?
謝謝,你是對的! – Alex
@David Caunt你能幫我解決這個http://stackoverflow.com/questions/19358095/core-data-reset – Ranjit