👀 Views: 58 💬 Answers: 1 📅 Created: 2025-06-12

ios objective-c uitableview networking Objective-C

I'm attempting to set up I've looked through the documentation and I'm still confused about I'm currently working on an iOS app where I need to fetch images from a remote server asynchronously and display them in a `UITableView`. While fetching the images, I notice that the UI becomes unresponsive, and at times, the images do not appear at all or only appear partially. I'm using `NSURLSession` for my network requests, but I'm facing a challenge with updating the UI after the images are fetched. Here's a simplified version of my code: ```objc - (void)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath]; NSString *imageUrl = self.imageUrls[indexPath.row]; cell.imageView.image = nil; // Clear existing image [self fetchImageFromURL:imageUrl completion:^(UIImage *image) { if (image) { cell.imageView.image = image; // Here I attempt to reload the specific cell but it doesn't seem to work dispatch_async(dispatch_get_main_queue(), ^{ [tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationNone]; }); } }]; return cell; } - (void)fetchImageFromURL:(NSString *)urlString completion:(void (^)(UIImage *))completion { NSURL *url = [NSURL URLWithString:urlString]; NSURLSessionDataTask *task = [self.session dataTaskWithURL:url completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { if (error) { NSLog(@"Error fetching image: %@", error); completion(nil); return; } UIImage *image = [UIImage imageWithData:data]; completion(image); }]; [task resume]; } ``` I also tried to call `cell.imageView setNeedsDisplay];` after assigning the image, but that didn't seem to help either. I'm concerned about performance issues and how to properly handle image loading without blocking the main thread. Additionally, I'm using Xcode 14.1 and targeting iOS 16. I would appreciate any insights on best practices for fetching and displaying images efficiently in a `UITableView` without causing UI glitches or delays. I'm working on a service that needs to handle this. I recently upgraded to Objective-C stable.