必须使用非nil布局参数初始化UICollectionView。 迅速与UICollectionView错误

Question

嗨，大家好，我收到以下错误-UICollectionView必须使用非nil布局参数初始化

适用于PopularShotsCollectionViewController-的代码：

import UIKit

private let reuseIdentifier = "Cell"

class PopularShotsCollectionViewController: UICollectionViewController {
    private var shots : [Shot] = [Shot](){
        didSet{
            self.collectionView?.reloadData()
        }
    }

    var API_URl = Config.SHOT_URL
    var shotPages = 1
    private let leftAndRightPaddings : CGFloat = 32.0
    private let numberOFItemsPerRow : CGFloat = 3.0
    private let heightAdjustMent : CGFloat = 30.0

    override func viewDidLoad() {
        super.viewDidLoad()
      // Do any additional setup after loading the view.
        let width = (CGRectGetWidth(collectionView!.frame) - leftAndRightPaddings) /  numberOFItemsPerRow
        let layout = collectionViewLayout as! UICollectionViewFlowLayout
        layout.itemSize = CGSizeMake(width, width + heightAdjustMent)


        let popularShot = PopularShotsCollectionViewController()
        popularShot.title = "Popular"
        popularShot.API_URl = Config.POPULAR_URL
        popularShot.loadShots()

    }

    func loadShots(){

      DribbleObjectHandler.getShots(API_URl) { (shots) -> Void in
        self.shots = shots
     }
     let refreshControl = UIRefreshControl()
        refreshControl.addTarget(self, action: Selector("refreshInvoked:"), forControlEvents: UIControlEvents.ValueChanged)
        collectionView?.addSubview(refreshControl)
}

    func refreshInvoked(sender : AnyObject){
      sender.beginRefreshing()
      collectionView?.reloadData()
      sender.endRefreshing()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

   // MARK: UICollectionViewDataSource

    override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of items
        return shots.count
    }

    override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! PopularShotsCollectionViewCell
        // Configure the cell
       let shot = shots[indexPath.row]
        cell.imageView.sd_setImageWithURL(NSURL(string : shot.imageUrl))

        if shots.count - 1 == indexPath.row && shotPages < 5{
          shotPages++
          print(shotPages)
          let url = API_URl + "&page=" + String(shotPages)
          DribbleObjectHandler.getShots(url, callback: { (shots) -> Void in
            for shot in shots {
              self.shots.append(shot)
            }
          })
        }

        return cell
    }
}

这是应用程序崩溃的地方

您也可以看看日志

如果我在此行之后尝试调试任何代码，它将自动崩溃而无需告知

我已经检查了Main.storyboard，什么也没有，这一切都应该将类连接到视图，委托和数据源也是如此

请记住，我只有12岁，对Swift来说还很陌生。任何帮助将不胜感激

在此先感谢Aryan Kashyap

Answer 1

我不明白为什么要在viewdidload中创建自身的新实例：

    let popularShot = PopularShotsCollectionViewController()
    popularShot.title = "Popular"
    popularShot.API_URl = Config.POPULAR_URL
    popularShot.loadShots()

我认为这可能是您陷入循环的问题？

你不能只是使用...

self.title = "Popular"
self.API_URl = Config.POPULAR_URL
self.loadShots()

加载collectionViewController时在viewDidLoad中...

看看那有什么不同