ios - 如何解决错误“viewController 对 swift 协议(protocol) UIScrollViewDelegate 的冗余一致性？

Question

我是 stackOverflow 的新手，正在快速学习。我收到错误 “在使用 Stretch headers.UIScrollViewDelegate 时，viewController 对协议(protocol)的冗余一致性。我在下面指定我的代码。请更正任何一个。

class ViewController: UITableViewController , UIScrollViewDelegate {
    private let kTableHeaderHeight : CGFloat = 300.0
    // Using Implicitly Unwrapped Optional, UIView!
    var headerView:UIView!

    let items = [
    NewsItem(category: .World, summary: "Climate Change protests, Need to preserve our Ecosysytem"),
    NewsItem(category: .India, summary: "Climate Change protests, Need to preserve our Ecosysytem"),
    NewsItem(category: .America, summary: "Climate Change protests,Need to preserve our Ecosysytem"),
    NewsItem(category: .Japan, summary: "Climate Change protests, Need to preserve our Ecosysytem"),
    NewsItem(category: .China, summary: "Climate Change protests, Need to preserve our Ecosysytem"),
    NewsItem(category: .Nepal, summary: "Climate Change protests, Need to preserve our Ecosysytem")]
    override func viewDidLoad() {
        super.viewDidLoad()
        headerView = tableView.tableHeaderView
        tableView.tableHeaderView = nil
        tableView.addSubview(headerView)
   tableView.contentInset = UIEdgeInsetsMake(kTableHeaderHeight, 0, 0, 0)
        tableView.contentOffset = CGPointMake(0, -kTableHeaderHeight)
        updateHeaderView()
    }
    func updateHeaderView(){
        var HeaderRect = CGRectMake(0,-kTableHeaderHeight, tableView.bounds.width, kTableHeaderHeight)

        if tableView.contentOffset.y < -kTableHeaderHeight{
            HeaderRect.origin.y = tableView.contentOffset.y
            HeaderRect.size.height = -tableView.contentOffset.y
        }
        headerView.frame = HeaderRect
    }
    override func didReceiveMemoryWarning() {enter code here
        super.didReceiveMemoryWarning()   
    }
    override func scrollViewDidScroll(scrollView: UIScrollView) {
        updateHeaderView()
    }
    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return items.count
    }
    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let item = items[indexPath.row]
let cell = tableView.dequeueReusableCellWithIdentifier("Cell" forIndexPath: indexPath) as! NewsItemTableViewCell
        cell.newsItem = item
 return cell          
    }

Answer 1

您收到此错误是因为您的类 ViewController 以两种方式符合协议(protocol) UIScrollViewDelegate。 UITableViewController 已经符合该协议(protocol)，您无需再次添加它。所以从那里删除 UIScrollViewDelegate，你很好。

这就是 UITableViewController 符合 UITableViewDelegate 而符合 UIScrollViewDelegate 的方式。这样就够了

class ViewController: UITableViewController{
}