ios - 从 customCell 访问 IBOutlet 到 ViewController

Question

我在 tableView 单元格中有一个 collectionView，我想调用 collectionView outlet 以通过重新加载它来更新我的 UI。我尝试了不同的方法，但因为零而崩溃。无论如何我可以做到这一点吗？

class CustomTableViewCell: UITableViewCell {
    @IBOutlet weak var collectionView: UICollectionView!   
}

class ViewController: UIViewController {

    @IBOutlet weak var tableView: UITableView!

    let identifier = "cell"

    var data = [CKRecord]()

    var sections = [customCollectionModel]()

    override func viewDidLoad() {
        super.viewDidLoad()
        sections = customCollectionModel.createSectionsArray()
        fetchDataFromCloud()
    }

    func fetchDataFromCloud() {
        books = [CKRecord]()
        books.removeAll()
       // Reload CollectionView here

        let container = CKContainer.default()
        let publicDatabase = container.publicCloudDatabase
        let predicate = NSPredicate(value: true)
        let query = CKQuery(recordType: "Book", predicate: predicate)
        query.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]

        let operation = CKQueryOperation(query: query)
        operation.desiredKeys = ["image"]
        operation.queuePriority = .veryHigh
        operation.resultsLimit = 25
        operation.recordFetchedBlock = { (record) -> Void in
            self.data.append(record)
        }
        operation.queryCompletionBlock = { (cursor, error) -> Void in
            if let error = error {
                print("Download failed \(error.localizedDescription)")
                return
            }

            print("Download Successful")

            OperationQueue.main.addOperation {
            // reload collectionView here
            }
        }
        operation.qualityOfService = .userInteractive

        publicDatabase.add(operation)
    }

Answer 1

当你像这样构造一个 View Controller 时:

var viewController = ViewController() 

socket 尚未连接(并且为零)——它们在 View 加载时连接，然后调用 viewDidLoad。在此函数中(或之后的任何时间)，outlets 不会为 nil。