我正在制作一个类似于 iPhone 日历 ListView 的视图。我正在使用核心数据并获得约会并按日期对它们进行分组。
但是，就像在 iPhone 列表视图中一样，即使没有约会，我也需要为今天添加一个空白部分。我无法弄清楚如何为没有约会的部分执行此操作，因为我在创建分组之前进行了排序。
我如何将一个空白部分添加到NSFetchedResultsController并使用它，以便今天的日期在正确的位置而不是在列表的末尾？
- (NSFetchedResultsController *)fetchedResultsController {
/*
Set up the fetched results controller.
*/
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Appointments" inManagedObjectContext:[[CoreDataHelper sharedInstance] managedObjectContext]];
[fetchRequest setEntity:entity];
//[fetchRequest setIncludesPendingChanges:YES];
// Set the batch size to a suitable number.
//[fetchRequest setFetchBatchSize:20];
// Sort using the date / then time property.
NSSortDescriptor *sortDescriptorDate = [[NSSortDescriptor alloc] initWithKey:@"date" ascending:YES];
NSSortDescriptor *sortDescriptorTime = [[NSSortDescriptor alloc] initWithKey:@"start_time" ascending:YES selector:@selector(localizedStandardCompare:)];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptorDate, sortDescriptorTime, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Use the sectionIdentifier property to group into sections.
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[[CoreDataHelper sharedInstance] managedObjectContext] sectionNameKeyPath:@"date" cacheName:nil];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
return fetchedResultsController;
}