在我的代码中,我想创建带有List部分的tableView。我使用的方案是这样一个:核心数据对多关系获取数据
我用NSFetchResultController我这样定义:
- (NSFetchedResultsController *)fetchedResultsController {
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription
entityForName:@"Item" inManagedObjectContext:coreDataController.masterManagedObjectContext];
[fetchRequest setEntity:entity];
NSSortDescriptor *sort = [[NSSortDescriptor alloc]
initWithKey:@"addedAt" ascending:YES];
[fetchRequest setSortDescriptors:[NSArray arrayWithObject:sort]];
[fetchRequest setFetchBatchSize:20];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"itemIsChecked = 1"];
[fetchRequest setPredicate:predicate];
[fetchRequest setResultType:NSDictionaryResultType];
NSFetchedResultsController *theFetchedResultsController =
[[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:coreDataController.masterManagedObjectContext sectionNameKeyPath:@"toList.listName"
cacheName:nil];
self.fetchedResultsController = theFetchedResultsController;
_fetchedResultsController.delegate = self;
return _fetchedResultsController;
}
现在的cellForRowAtIndexPath:我想要得到的数据形成我的fetchResultController,所以我这样做在方式:
Item *item = [self.fetchedResultsController objectAtIndexPath:indexPath];
,然后,如果我想访问该项目的(例如itemText),它坠毁现场之一:
NSLog(@"item itemtext = %@", item.itemText);
错误:
-[NSKnownKeysDictionary1 itemText]: unrecognized selector sent to instance 0x1215fd90
我该怎么办错在我的代码?
完美诊断.. +1。 –
很好的答案,谢谢马丁! – edzio27