Swift 4 - 垂直 UICollectionView 上的 UIRefreshControl 滞后

Question

出于某种原因，我的拉动刷新真的很难完成。我的意思是，为了拉动刷新，我必须从我的收藏视图的最顶部开始并向下滚动到最底部......有时我什至必须用第二根手指才能滚动更多以使其工作！

这是我初始化刷新器的方法：

private var refresher: UIRefreshControl!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.

    refresher = UIRefreshControl()

    refresher.addTarget(self, action: #selector(self.requestRefreshContent), for: .valueChanged)

    if #available(iOS 10.0, *) {
        schoolPostsCollectionView.refreshControl = refresher
    }
    else {
        schoolPostsCollectionView.addSubview(refresher)
    }

    refresher.beginRefreshing()
}

我是这样称呼beginRefreshing()的：

private func getContentOfSchool() {
    someBackgroundServerCall() {
        // some code

        ...

        DispatchQueue.main.async {
            self.refresher.endRefreshing()
            self.schoolPostsCollectionView.reloadData()
        }
    }
}

知道为什么会这样吗？

Answer 1

试试这个....

refresher = UIRefreshControl()
    refresher.attributedTitle = NSAttributedString(string: "Refreshing...", attributes: nil)
    refresher.tintColor = UIColor.black
    refresher.addTarget(self, action: #selector(self.requestRefreshContent), for: .valueChanged)

    if #available(iOS 10.0, *) {
        schoolPostsCollectionView.refreshControl = refresher
    } else {
        schoolPostsCollectionView.backgroundView = refresher
    }