👀 Views: 3 💬 Answers: 1 📅 Created: 2025-06-06

objective-c uitableview gcd Objective-C

Quick question that's been bugging me - I'm working with a crash when trying to update my UITableView with new data fetched from a network request. I use Grand Central Dispatch (GCD) to fetch data in the background, but when I try to update the UI, it crashes with the behavior: `Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'reloadData() called while enumerating'.` Here's a simplified version of my code: ```objective-c dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ NSArray *newData = [self fetchDataFromServer]; // This fetches data from a network call dispatch_async(dispatch_get_main_queue(), ^{ self.dataArray = newData; // Update the data source [self.tableView reloadData]; // Crash occurs here }); }); ``` I've tried wrapping the `reloadData` call in a `@try` block to catch exceptions, but it still crashes. Additionally, I have verified that `fetchDataFromServer` is returning valid data. I suspect that the crash is happening because I'm modifying the `dataArray` while the UITableView is still processing its current data. How can I safely update the UITableView with the new data without causing this crash? I'm using Xcode 14.1 and targeting iOS 15.0. Any insights or best practices would be greatly appreciated. This issue appeared after updating to Objective-C latest. I'm coming from a different tech stack and learning Objective-C. Thanks for any help you can provide!