分页问题

Question

我正在尝试在我的iOS应用中使用Instagram API for Pagination。但是每当我将新图片添加到现有数组时，我都会收到此错误：

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFArray insertObject:atIndex:]: mutating method sent to immutable object'

这是关于如何获取初始Instagram图像集的代码：

- (void)fetchInstagramPics {
    NSUserDefaults *user = [NSUserDefaults standardUserDefaults];
    BOOL *status = [user boolForKey:@"isInstagramLoggedIn"];
    if (status) {
        [[InstagramClient sharedClient] getPath:@"users/self/feed"
                                     parameters:nil
                                        success:^(AFHTTPRequestOperation *operation, id responseObject) {
                                            // NSLog(@"Response: %@", responseObject);
                                            self.timelineResponse = [responseObject mutableCopy];
                                            [instaPics addObjectsFromArray:responseObject[@"data"]];
                                            [self updateArrays];
                                            [self.tableView reloadData];
                                        } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
                                            NSLog(@"Failure: %@", error);
                                        }];
    }
    dispatch_async(dispatch_get_main_queue(), ^{
        [self.tableView reloadData]; });
}

以下是我尝试将更多图片添加到instaPics数组中的方法：

- (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.timelineResponse = [responseObject mutableCopy];
        [self.timelineResponse addEntriesFromDictionary:responseObject];
        [instaPics addObjectsFromArray:responseObject[@"data"]];
        [self.tableView reloadData];

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Failure: %@", error);
    }];
}

- (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 nextInstagramPage:indexPath];
    }
}

以下是此类的Header文件中定义的所有属性：

@property (strong, nonatomic) NSMutableArray *instaPics;
@property (strong, nonatomic) AFOAuth1Client *twitterClient;
@property (strong, nonatomic) IBOutlet UINavigationItem *navBar;
@property (strong, nonatomic) NSMutableArray *tweets;

//编辑：现在有了细胞的构造：

if (indexPath.row % 2 == 0)  {
            static NSString *CellIdentifier = @"TweetCell";
            UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
            cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"Background.png"]];

            NSDictionary *tweet = tweets[indexPath.row];

            return cell;

        }else {

            static NSString *CellIdentifier = @"InstagramCell";
            UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
            cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"Background.png"]];

            NSDictionary *entry = instaPics[indexPath.row];

            return cell;
        }

}

Answer 1

您必须初始化NSMutableArray，在instaPics = [[NSMutableArray alloc] init];

中添加fetchInstagramPics