数组objectAtIndex：超出界限的错误

所以最近，我很难找出如何创build一个uicollectionview的search栏（请看这里 ）。 幸运的是，有人能够为我回答。 但是，由于滚动我的应用程序是非常缓慢和越野车，我决定实施一个asynchronous的请求，使图像加载在后台，并因此加载，更快。

问题是我的包含search查询的数组无法“重新加载”我的uicollectionview，因为asynchronous请求正在干扰它。 或者至less，这就是我认为的问题，如果问题在别的地方，请告诉我。

这是我不断收到的错误消息：

2014-07-21 16:28:22.199 A Great App for TF2[545:70b] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]' *** First throw call stack: ( 0 CoreFoundation 0x01c2e5e4 __exceptionPreprocess + 180 1 libobjc.A.dylib 0x019b18b6 objc_exception_throw + 44 2 CoreFoundation 0x01bcf4e6 -[__NSArrayM objectAtIndex:] + 246 3 CoreFoundation 0x01cad608 -[NSArray objectAtIndexedSubscript:] + 40 4 A Great App for TF2 0x0001ebf1 __62-[MasterViewController collectionView:cellForItemAtIndexPath:]_block_invoke + 289 5 Foundation 0x016cd695 __67+[NSURLConnection sendAsynchronousRequest:queue:completionHandler:]_block_invoke_2 + 151 6 Foundation 0x0162d945 -[NSBlockOperation main] + 88 7 Foundation 0x01686829 -[__NSOperationInternal _start:] + 671 8 Foundation 0x01603558 -[NSOperation start] + 83 9 Foundation 0x01688af4 __NSOQSchedule_f + 62 10 libdispatch.dylib 0x063454b0 _dispatch_client_callout + 14 11 libdispatch.dylib 0x0633375e _dispatch_main_queue_callback_4CF + 340 12 CoreFoundation 0x01c93a5e __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 14 13 CoreFoundation 0x01bd46bb __CFRunLoopRun + 1963 14 CoreFoundation 0x01bd3ac3 CFRunLoopRunSpecific + 467 15 CoreFoundation 0x01bd38db CFRunLoopRunInMode + 123 16 GraphicsServices 0x02fce9e2 GSEventRunModal + 192 17 GraphicsServices 0x02fce809 GSEventRun + 104 18 UIKit 0x0071fd3b UIApplicationMain + 1225 19 A Great App for TF2 0x000235dd main + 141 20 libdyld.dylib 0x065d770d start + 1 ) libc++abi.dylib: terminating with uncaught exception of type NSException (lldb) 

我的代码

这是相当长的，因为我使用一个长的书面api调用来生成我收集视图中的单元格。 我会尽力去除代码中不必要的部分。

MasterViewController.m

 @interface MasterViewController () <SteamManagerDelegate> { NSArray *_groups; NSArray *_itemGroups; NSArray *_backpackItems; NSArray *_backpackItemPhotos; SteamManager *_manager; } @property (nonatomic, strong) NSMutableArray *dataSource, *originalDataSource, *backpackSource; @end @implementation MasterViewController - (void)viewDidLoad { [super viewDidLoad]; self.collectionView.dataSource = self; self.collectionView.delegate = self; self.automaticallyAdjustsScrollViewInsets = NO; UISearchBar *searchBar = [UISearchBar new]; searchBar.delegate = self; searchBar.showsCancelButton = YES; self.navigationItem.titleView = searchBar; _manager = [[SteamManager alloc] init]; _manager.communicator = [[SteamCommunicator alloc] init]; _manager.communicator.delegate = _manager; _manager.delegate = self; [self startFetchingGroups]; loadingView = [[UIView alloc] initWithFrame:CGRectMake(75, 155, 170, 170)]; loadingView.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.5]; loadingView.clipsToBounds = YES; loadingView.layer.cornerRadius = 10.0; activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge]; activityView.frame = CGRectMake(65, 40, activityView.bounds.size.width, activityView.bounds.size.height); [loadingView addSubview:activityView]; loadingLabel = [[UILabel alloc] initWithFrame:CGRectMake(20, 115, 130, 22)]; loadingLabel.backgroundColor = [UIColor clearColor]; loadingLabel.textColor = [UIColor whiteColor]; loadingLabel.adjustsFontSizeToFitWidth = YES; loadingLabel.textAlignment = UITextAlignmentCenter; loadingLabel.text = @"Loading..."; [loadingView addSubview:loadingLabel]; [self.view addSubview:loadingView]; [activityView startAnimating]; } #pragma mark - Notification Observer - (void)startFetchingGroups { [_manager fetchGroups]; } #pragma mark - SteamManagerDelegate - (void)didReceiveGroups:(NSArray *)groups { _groups = groups; } - (void)didReceieveItemGroups:(NSArray *)groups { _itemGroups = groups; _backpackItems = [self createBackpackIcons:_groups usingItemGroups:_itemGroups]; _dataSource = [[NSMutableArray alloc] init]; for(NSUInteger i = 0; i < _backpackItems.count; i++){ backpackIcons *items = _backpackItems[i]; [_dataSource addObject:items.name]; } self.originalDataSource = self.dataSource; dispatch_async(dispatch_get_main_queue(), ^{ [self.collectionView reloadData]; [activityView stopAnimating]; [loadingView removeFromSuperview]; }); } #pragma mark - Collection View - (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section { return _groups.count; } - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{ static NSString *identifier = @"Cell"; backpackIcons *item = _backpackItems[indexPath.row]; NSString *photoURL = item.image_url; NSString *quality = item.quality; UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath]; UIImageView *itemImageView = (UIImageView *)[cell viewWithTag:100]; UILabel *itemName = (UILabel *) [cell viewWithTag:110]; NSLog([NSString stringWithFormat:@"%d", _dataSource.count]); //backpackIcons *item1 = _dataSource[indexPath.row]; NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:photoURL]]; [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) { [itemImageView setImage:[UIImage imageWithData:data]]; [itemName setText:_dataSource[indexPath.row]]; }]; /*itemImageView.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:photoURL]]];*/ [itemImageView setBackgroundColor:Rgb2UIColor(60, 53, 46)]; if([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"6"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(125, 109, 0) CGColor]]; } else if([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"1"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(77, 116, 85) CGColor]]; } else if ([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"3"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(71, 98, 145) CGColor]]; } else if ([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"5"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(134, 80, 172) CGColor]]; } else if ([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"11"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(207, 106, 50) CGColor]]; } else if ([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"7"] || [[NSString stringWithFormat:@"%@", quality] isEqualToString:@"9"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(112, 176, 74) CGColor]]; } else if ([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"8"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(165, 15, 121) CGColor]]; } else if ([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"0"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(178, 178, 178) CGColor]]; } else if ([[NSString stringWithFormat:@"%@", quality] isEqualToString:@"13"]) { [itemImageView.layer setBorderColor:[Rgb2UIColor(56, 243, 171) CGColor]]; } else { [itemImageView.layer setBorderColor:[Rgb2UIColor(170, 0, 0) CGColor]]; } [itemImageView.layer setBorderWidth: 1.0]; return cell; } #pragma mark UISearchBarDelegate - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar { [self applyFilters:[NSSet setWithObject:searchBar.text]]; [searchBar resignFirstResponder]; } - (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar { [searchBar resignFirstResponder]; } - (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText { if (![searchText length]) { self.dataSource = self.originalDataSource; [self.collectionView reloadData]; } } #pragma mark private - (void)applyFilters:(NSSet *)filters { NSMutableArray *newData = [NSMutableArray array]; for (NSString *s in self.dataSource) { for (NSString *filter in filters) { if ([s rangeOfString:filter].location != NSNotFound) { [newData addObject:s]; break; } } } self.dataSource = newData; [self.collectionView reloadData]; } 

如果您想下载我的项目以单独查看文件，请访问此处 。 这个类被称为MasterViewController.m。

任何帮助将不胜感激。