如何从另一个函数触发 UICollectionView 的 reload 方法

Question

我有一个 UICollection 视图，它在我启动应用程序时加载得很好。我的问题是，当单击菜单栏中的按钮时，我需要用新数据重新加载它。这是我的代码。为了简单起见，我已经大大缩减了它

    class RootViewController:  UIViewController,UICollectionViewDelegateFlowLayout, UICollectionViewDataSource{//The view controller that contains the collection view
        var carouselCollectionView: UICollectionView!//A reference to the collectionview
        override func viewDidLoad() {
            super.viewDidLoad()

            let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
            layout.sectionInset = UIEdgeInsets(top: 1, left: 1, bottom: 1, right: 1)
            layout.itemSize = CGSize(width: carouselWindowWidth, height: carouselWindowHeight)
            layout.scrollDirection = UICollectionViewScrollDirection.Horizontal
            layout.minimumInteritemSpacing = 5
            layout.minimumLineSpacing = 5

            carouselCollectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
            carouselCollectionView.frame = CGRectMake(0,0,200,200)
            carouselCollectionView.delegate = self
            carouselCollectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
            carouselCollectionView.backgroundColor = UIColor.clearColor()

            self.view.addSubview(carouselCollectionView) //Add the collectionview to the main view(self)
        }//End viewDidLoad


        //Delegates for collectionViewController go here
        func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
            return currentImageArray.count
        }


        func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
            let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath)
            /*...*/
         }

         func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
             /*...*/
         }


         //This function is triggered when a menuItem on the menuBar is clicked.  It it supposed to fetch some data from some source, then reload the collectionview
        func reloadData(VC:UIViewController){
            /*...*/
            carouselCollectionView.reloadData()
        }

    }//End RootViewController

reloadData() 运行时出现此错误

致命错误：在展开可选值时意外发现 nil

关于如何正确执行此操作的任何想法？非常感谢任何帮助

PS。当我在viewDidLoad() 中运行reloadData() 时，数据符合预期

Answer 1

好的，您需要通过 2 个步骤来处理这个问题：

1. 创建集合视图的@IBOutlet 并将其与情节提要中的集合视图连接：yourCollectionView

2. 声明并初始化：var currentImageArray = UIImage

3. 在按钮的@IBAction 上：

// 做你的事 // 然后

你的CollectionView.reloadData()

什么时候可以告诉我！！！