Question

当我向UITableView添加单元格时，它们按字母顺序排序。当我重新加载视图时，它们按timeStamp排序。我希望它们按时间顺序按时间排序，而不是按字母顺序排序。

这是我添加单元格的地方：

-(IBAction)createSet
{    
    Set *set = (Set *)[NSEntityDescription insertNewObjectForEntityForName:@"Set" inManagedObjectContext:managedObjectContext];
    set.weight = [NSNumber numberWithFloat:weightSelected2];
    set.reps = [NSNumber numberWithInt:repSelected];
    set.timeStamp = self.picker.date;
    [self.exercise addSetsObject:set];

    NSError *error = nil;
    if (![managedObjectContext save:&error]) 
    {
        // Handle the error.
    }
    NSLog(@"error: %@", error);
    [setsTableView reloadData];
}

这是我的fetchedResultsController：

- (NSFetchedResultsController *)fetchedResultsController
{
    if (fetchedResultsController != nil)
    {
        return fetchedResultsController;
    }
    // Create the fetch request for the entity.
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    // Edit the entity name as appropriate.
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Set" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];
    [fetchRequest setPredicate:[NSPredicate predicateWithFormat: @"sets == %@", self.exercise]];
    // Set the batch size to a suitable number.
    [fetchRequest setFetchBatchSize:20];
    // Edit the sort key as appropriate.
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"timeStamp" ascending:YES];
    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

    [fetchRequest setSortDescriptors:sortDescriptors];

    // Edit the section name key path and cache name if appropriate.
    // nil for section name key path means "no sections".
    NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
    aFetchedResultsController.delegate = self;
    self.fetchedResultsController = aFetchedResultsController;

    [aFetchedResultsController release];
    [fetchRequest release];
    [sortDescriptor release];
    [sortDescriptors release];

    NSError *error = nil;
    if (![self.fetchedResultsController performFetch:&error])
    {
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }
    return self.fetchedResultsController;
}

Answer 1

尝试在添加单元格后重新加载表格。

将单元格添加到UITableView时调整排序

1 个答案: