UITableView和UICollectionView更新新单元格问题

Question

I am trying to work with UICollectionView that is a part of the UITableViewCell.

So the issue I faced, the collection view for visible table cells works ok, but when I start scroll table and table starts create new cells that where invisible then I faces with some behaviour that duplicate first table cell. For example I have scrolled collection view in first table view cell, then I scrolled table view down, and what I see the new cell have the same state as my first cell had. You can check source here repo and the video here to understand what I am talking about.

Answer 1

-[UITableViewCell prepareForReuse]

Answer 2

Have a property of UICollectionView in CustomTableViewCell.h and bind it in Main.storyboard. Let's assume declared it like this:

@property (strong, nonatomic) UICollectionView *collectionView;

In ViewController.m change cellForRowAtIndexPath method, so it reloads inside UICollectionView every time it need

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

    [cell.collectionView reloadData];
    [cell.collectionView scrollRectToVisible:CGRectZero animated:NO];

    return cell;
}

Of course, you need to import CustomTableViewCell.h on ViewController.m file.

Answer 3

Problem with reuse identifier in UITableView cell, if you use single cell identifier in cellForRowAtIndexPath this problem will occurs

1. Use Dynamic cell identifier for each row, like this

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    CustomTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:[NSString stringWithFormat:@"CustomTableViewCell_%d",indexPath.row]];
}

2.Store content offset for each collection view in array, and reset collection view content offset

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    ......
    [cell.collectionView setContentOffset:scrollingPoint animated:NO];

    return cell;
}