Question

我的tableview充满了fetchedresultscontroller和searchbar。到目前为止，在创建应用程序的时候，我只使用了7个单元格并且运行良好，但是由于我开始使用超过7个单元格，当我触摸搜索栏时，我得到了超出界限的空数组错误。但是当我把它还原回到7个细胞时，它完美无缺。

可能出现什么问题？

错误：由于未被捕获的异常“NSRangeException”导致应用程序停止，原因：' * -[__NSArrayM objectAtIndex:]:索引2超出空数组的范围'

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.title = @"Exercises";



    id appDelegate = [[UIApplication sharedApplication] delegate];
    _managedObjectContext = [appDelegate managedObjectContext];

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

    _searchResults = [[NSMutableArray alloc] init];


}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    NSIndexPath *selectedIndexPath = [_tableView indexPathForSelectedRow];
    if (!selectedIndexPath) {
        [_tableView setContentOffset:CGPointMake(0, 44) animated:NO];
    }
    else {
        [_tableView deselectRowAtIndexPath:selectedIndexPath animated:YES];
    }
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
    if (self.searchDisplayController.isActive) {
        [self.searchDisplayController setActive:NO animated:YES];
    }
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

#pragma mark - UITableViewDataSource

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    if (self.searchDisplayController.isActive) {
        return 1;
    }
    return [[_fetchedResultsController sections] count];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    if (self.searchDisplayController.isActive) {
        return nil;
    }
    return [[[_fetchedResultsController sections] objectAtIndex:section] name];
}

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 22)];
    view.backgroundColor = [UIColor colorWithRed:20.0/255.0 green:20.0/255.0 blue:20.0/255.0 alpha:0.8];

    UILabel *sectionLabel = [[UILabel alloc] initWithFrame:CGRectMake(20, 0, 160, 22)];
    sectionLabel.font = [UIFont fontWithName:@"Avenir-Book" size:16.0f];
    sectionLabel.text = @"Search Results";

    if (!self.searchDisplayController.isActive) {
        sectionLabel.text = [[[_fetchedResultsController sections] objectAtIndex:section] name];
    }

    sectionLabel.backgroundColor = [UIColor clearColor];
    sectionLabel.textColor = [UIColor whiteColor];
    [view addSubview:sectionLabel];
    return view;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (self.searchDisplayController.isActive) {
        return [_searchResults count];
    }
    return [[[_fetchedResultsController sections] objectAtIndex:section] numberOfObjects];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"exerciseCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
        [self stampCell:cell atIndexPath:indexPath];
    }

    [self configureCell:cell atIndexPath:indexPath];

    return cell;
}


#pragma mark - Cell

- (void)stampCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
    if ([cell.reuseIdentifier isEqualToString:@"exerciseCell"]) {

        UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 2, 150, 22)];
        textLabel.tag = kExerciseCellTextLabel;
        textLabel.font = [UIFont systemFontOfSize:18.0];
        textLabel.textColor = [UIColor blackColor];
        textLabel.highlightedTextColor = [UIColor whiteColor];
        textLabel.backgroundColor = [UIColor clearColor];
        [cell.contentView addSubview:textLabel];

        UILabel *detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 24, 150, 18)];
        detailTextLabel.tag = kExerciseCellDetailTextLabel;
        detailTextLabel.font = [UIFont systemFontOfSize:14.0];
        detailTextLabel.textColor = [UIColor colorWithRed:128.0/255.0 green:128.0/255.0 blue:128.0/255.0 alpha:1.0];
        detailTextLabel.highlightedTextColor = [UIColor colorWithRed:127.0/255.0 green:127.0/255.0 blue:127.0/255.0 alpha:1.0];
        detailTextLabel.backgroundColor = [UIColor clearColor];
        [cell.contentView addSubview:detailTextLabel];

    }
}

- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
    if ([cell.reuseIdentifier isEqualToString:@"exerciseCell"]) {

        UILabel *textLabel = (UILabel *)[cell.contentView viewWithTag:kExerciseCellTextLabel];
        UILabel *detailTextLabel = (UILabel *)[cell.contentView viewWithTag:kExerciseCellDetailTextLabel];

        Exercise *exercise;

        if (self.searchDisplayController.isActive) {
            exercise = [_searchResults objectAtIndex:indexPath.row];
        }
        else {
            exercise = [_fetchedResultsController objectAtIndexPath:indexPath];
        }

        textLabel.text = [exercise valueForKey:kExerciseName];
        detailTextLabel.text = [NSString stringWithFormat:@"%@ - %@", [[exercise valueForKey:kExerciseEType] valueForKey:kExerciseTypeName], [[exercise valueForKey:kExerciseGear] valueForKey:kGearName]];

        cell.selectionStyle = UITableViewCellSelectionStyleGray;
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

    }
}


#pragma mark - UITableViewDelegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [self performSegueWithIdentifier:@"exerciseDetail" sender:self];
}

#pragma mark - UISearchBarDelegate

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
    [_searchResults removeAllObjects];
    if (searchString.length > 0) {

        for (Exercise *exercise in [_fetchedResultsController fetchedObjects]) {
            NSRange range = [[exercise valueForKey:kExerciseName] rangeOfString:searchString options:NSCaseInsensitiveSearch];
            if (range.location == 0) {
                [_searchResults addObject:exercise];
            }
        }
    }
    return YES;
}

- (BOOL)searchBarShouldBeginEditing:(UISearchBar*)searchBar {
    [super setPan];
    return YES;
}

- (BOOL)searchBarShouldEndEditing:(UISearchBar *)searchBar
{
    [super setPan];
    return YES;
}

#pragma mark - NSFetchedResultsControllerDelegate

- (NSFetchedResultsController *)fetchedResultsController
{
    if (_fetchedResultsController) {
        return _fetchedResultsController;
    }

    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:kExercise inManagedObjectContext:_managedObjectContext];
    [request setEntity:entity];

    NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:kExerciseName ascending:YES];
    [request setSortDescriptors:[NSArray arrayWithObject:sort]];

    NSFetchedResultsController *fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:_managedObjectContext sectionNameKeyPath:kExerciseFirstLetter cacheName:@"ExerciseList"];
    [self setFetchedResultsController:fetchedResultsController];
    [_fetchedResultsController setDelegate:self];

    return _fetchedResultsController;
}

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

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
    switch(type) {
        case NSFetchedResultsChangeInsert:
            [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
       atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
      newIndexPath:(NSIndexPath *)newIndexPath
{
    UITableView *tableView = self.tableView;

    switch(type) {
        case NSFetchedResultsChangeInsert:
            [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;

        case NSFetchedResultsChangeUpdate:
            [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
            break;

        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
            [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
            break;
    }
}

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

@end

Answer 1

它显示有些阵列仍然是空的......更好的检查方法

- 在数组元素之后输出NSLog语句并运行它.IT显示哪个数组保持为空。

通过这样做，如果你的问题没有得到解决..请让我知道..所以，我可以帮助你进一步..

Answer 2

你在哪里看到崩溃 - 只显示搜索结果或显示整个列表？

如果仅搜索结果，则_searchResults的记录不会超过7条。

如果是在显示所有结果时，请检查_fetchedResultsController.sections的每个值中的记录数。看起来他们的记录不超过7条。

Answer 3

嗨我想你从_searchResults删除所有元素可能是由于这个应用程序崩溃了。请检查一次。

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
    [_searchResults removeAllObjects];

Tableview使用空数组获取索引超出范围

3 个答案: