小编J.G*_*Han的帖子

这是我要实现的目标的高级描述；1. 获取数据 2. 将获取的数据保存在数组对象中 3. 使用数组的大小更新集合视图

这是我的代码

class ItemcollectionViewController:UICollectionViewController, UICollectionViewDelegateFlowLayout {

  let cellId = "CellId"
  var categories = [Category]()
  let viewOptionVar:ViewOptionBar = {
      let vOV = ViewOptionBar()
      vOV.translatesAutoresizingMaskIntoConstraints = false
      return vOV
  }()

  private func fetchData() {
      let categoryController = CategoryController()
      categoryController.getAllCategory(username: "blah", password: "password") {(returnedCategories, error) -> Void in
            if error != nil {
               print(error)
               return
            }
            self.categories = returnedCategories!
            print("size of the array is \(self.categories.count)")
            OperationQueue.main.addOperation{self.collectionView?.reloadData()}
      }

  }

  override func viewDidLoad() {
    super.viewDidLoad()
    fetchData()
    collectionView?.backgroundColor = UIColor.white
    collectionView?.register(ItemCell.self, …