最近，我无法弄清楚如何为uicollectionview创建搜索栏（请查看here）。幸运的是，有人能够为我回答。但是，因为我的应用程序的滚动非常慢而且有错误，所以我决定实现一个异步请求，使图像在后台加载，从而更快地加载。
问题是我的包含搜索查询的数组无法“重新加载”我的uicollectionview，因为异步请求正在干扰它。或者至少，这就是我认为问题所在，如果问题出在其他地方，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
这很长，因为我使用长写的api调用来在我的集合视图中生成单元格。我会尝试删除不必要的代码部分。
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该文件，请访问here。 该类称为MasterViewController.m。
非常感谢任何帮助。