添加更多单元格UICollectionView
那么现在我正在从Instagram取代我的图片到屏幕的底部，而不是添加新的单元格。 我将如何添加新的单元格而不是replace以前的单元格？
这是我的完整实现文件来检索图像的下一页：
@interface StreamViewController () <UITextFieldDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout> @property (nonatomic, strong) NSMutableDictionary *timelineResponse; @property (nonatomic, strong) CredentialStore *credentialStore; @property (weak, nonatomic) IBOutlet UICollectionView *collectionView; @end @implementation StreamViewController - (void)viewDidLoad { [super viewDidLoad]; [self refreshInstagram]; //Refresh UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init]; [refreshControl addTarget:self action:@selector(startRefresh:) forControlEvents:UIControlEventValueChanged]; [self.collectionView addSubview:refreshControl]; //Instigate Navigation Bar Buttons UIButton *barButton = [UIButton buttonWithType:UIButtonTypeCustom]; [barButton setTitle:@"" forState:UIControlStateNormal]; [barButton setBackgroundImage:[UIImage imageNamed:@"barButton.png"] forState:UIControlStateNormal]; [barButton setBackgroundImage:[UIImage imageNamed:@"barButton_s.png"] forState:UIControlStateHighlighted]; [barButton addTarget:self action:@selector(didTapBarButton:) forControlEvents:UIControlEventTouchUpInside]; barButton.frame = CGRectMake(0.0f, 0.0f, 30.0f, 30.0f); UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:barButton]; self.navBar.leftBarButtonItem = barButtonItem; UIButton *postButton = [UIButton buttonWithType:UIButtonTypeCustom]; [postButton setTitle:@"" forState:UIControlStateNormal]; [postButton setBackgroundImage:[UIImage imageNamed:@"pen_usIMG.png"] forState:UIControlStateNormal]; [postButton setBackgroundImage:[UIImage imageNamed:@"pen_sIMG.png"] forState:UIControlStateHighlighted]; [postButton addTarget:self action:@selector(didTapPostButton:) forControlEvents:UIControlEventTouchUpInside]; postButton.frame = CGRectMake(0.0f, 0.0f, 30.0f, 30.0f); UIBarButtonItem *postButtonItem = [[UIBarButtonItem alloc] initWithCustomView:postButton]; self.navBar.rightBarButtonItem = postButtonItem; //Reload by default [self.collectionView reloadData]; } //Global refresh Instagram Method - (void)refreshInstagram { [[InstagramClient sharedClient] getPath:@"users/self/feed" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) { NSLog(@"Response: %@", responseObject); self.timelineResponse = responseObject; [self.collectionView reloadData]; } failure:^(AFHTTPRequestOperation *operation, NSError *error) { NSLog(@"Failure: %@", error); }]; } - (void)nextInstagramPage:(NSIndexPath *)indexPath{ NSDictionary *page = self.timelineResponse[@"pagination"]; NSString *nextPage = page[@"next_url"]; [[InstagramClient sharedClient] getPath:[NSString stringWithFormat:@"%@",nextPage] parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) { [self.collectionView cellForItemAtIndexPath:indexPath]; self.timelineResponse = [responseObject mutableCopy]; [self.timelineResponse addEntriesFromDictionary:responseObject]; [self.collectionView reloadData]; } failure:^(AFHTTPRequestOperation *operation, NSError *error) { NSLog(@"Failure: %@", error); }]; } - (NSMutableArray *)entries { return self.timelineResponse[@"data"]; } - (NSArray *)pages { return self.timelineResponse[@"pagination"]; } - (NSURL *)imageUrlForEntryAtIndexPath:(NSIndexPath *)indexPath { NSDictionary *entry = [self entries][indexPath.row]; NSString *imageUrlString = entry[@"images"][@"standard_resolution"][@"url"]; return [NSURL URLWithString:imageUrlString]; } #pragma mark - UICollectionViewDelegate - (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath { //int y = arc4random() % 200+50; return CGSizeMake(150, 150); } - (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath { RNBlurModalView *modal = [[RNBlurModalView alloc] initWithViewController:self title:@"Item Tapped!" message:@"Thank God its working"]; [modal show]; } - (void)scrollViewDidScroll:(UIScrollView *)scrollView { if (scrollView.contentOffset.y == roundf(scrollView.contentSize.height-scrollView.frame.size.height)) { NSLog(@"we are at the endddd"); NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0]; [self.collectionView performBatchUpdates:^{ [self nextInstagramPage:indexPath]; } completion:^(BOOL finished) { } ]; } } #pragma mark - UICollectionViewDataSource -(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section { return [[self entries] count]; } -(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath { if ( indexPath.item == ([[self entries] count] - 1) ) { // download more data and add it to the 'entries' array [self refreshInstagram]; } ImageCell *cell = (ImageCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"imageCell" forIndexPath:indexPath]; NSURL *url = [self imageUrlForEntryAtIndexPath:indexPath]; NSLog(@"%@", url); [cell.imageView setImageWithURL:url]; cell.backgroundColor = [UIColor whiteColor]; return cell; } -(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView { return 1; } #pragma mark - NavigationBarButtons - (void)didTapBarButton:(id)sender { [self.sidePanelController showLeftPanelAnimated:YES]; } - (void)startRefresh:(UIRefreshControl *)sender { [self refreshInstagram]; [sender endRefreshing]; } -(void)didTapPostButton:(id)sender { } @end 以下是添加新单元格的方法：
-(void)addNewCells { [self.collectionView performBatchUpdates:^{ int resultsSize = [[self entries]count]; [self.results addObjectsFromArray:newData]; NSMutableArray *arrayWithIndexPaths = [NSMutableArray array]; for (int i = resultsSize; i < resultsSize + newData.count; i++) [arrayWithIndexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]]; } [self.collectionView insertItemsAtIndexPaths:arrayWithIndexPaths]; } completion:nil]; }
你将不得不保留从服务返回的照片的数组 。 正如蒙迪的答案所暗示的那样，字典将不起作用，因为从字典中添加响应将取代现有的键/值对。 这就是为什么你看到闪烁。
将一个NSMutableArray属性添加到您的视图控制器，并从数据中添加条目。
[self.photosArray addObjectsFromArray:responseObject[@"data"]];
然后在你的entries方法中用户self.photosArray 。
你只需增加你的数据数组。 将timelineResponse放入一个NSMutableArray和
[self.timelineResponse addObjectsFromArray：responseObject];
[self.timelineResponse addEntriesFromDictionary:responseObject]; [self.collectionView reloadData];