👀 Views: 48 💬 Answers: 1 📅 Created: 2025-07-27

ios uicollectionview swift

I'm confused about I'm having trouble with I'm experiencing an issue where my UICollectionView cells are not updating their content after calling `reloadData()`. I have a custom layout that relies on dynamically calculated sizes based on the data model. After fetching new data from the server, I update my data source and call `reloadData()`, but the cells are displaying stale content. Here's a snippet of my data update and reload code: ```swift func fetchData() { // Simulate a network fetch DataService.fetchNewData { newData in self.dataSource = newData DispatchQueue.main.async { self.collectionView.reloadData() } } } ``` I've confirmed that `self.dataSource` contains the new data after the fetch, but the cells are still displaying the old values. I’ve also tried calling `invalidateLayout()` on my custom UICollectionViewLayout before the reload, but it didn't help. Here's how I've set up my UICollectionView and layout: ```swift collectionView = UICollectionView(frame: .zero, collectionViewLayout: CustomFlowLayout()) collectionView.dataSource = self collectionView.delegate = self ``` In the `cellForItemAt` method, I ensure I populate the cell correctly: ```swift func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "MyCell", for: indexPath) as! MyCustomCell cell.configure(with: dataSource[indexPath.item]) return cell } ``` I’ve checked to ensure that the correct data is being passed into the `configure` method of my custom cell, and it appears to be correct. The cells visually update in the simulator, but when running on an actual device, they don’t reflect the new data until I perform a manual pull-to-refresh. Is there something I might be missing in terms of layout invalidation or caching? Any insights would be greatly appreciated! For context: I'm using Swift on CentOS. I'm developing on CentOS with Swift. Thanks, I really appreciate it! Any examples would be super helpful.