View Controller中的嵌入式UICollectionView未被调用Swift

Question

由于一些奇怪的原因，没有调用collectionView。我把断点放在numberOfItemsInSection和cellForItemAtIndexPath但是从不调用它们。这是我的代码：

class ChannelViewController: UIViewController, UISearchResultsUpdating, UICollectionViewDataSource, UICollectionViewDelegate {

  var channelArray: [ChannelInfo] = []
  var filteredSearchResults = [ChannelInfo]()
  var resultsSearchController = UISearchController(searchResultsController: nil)
  var logosShown = [Bool](count: 50, repeatedValue: false)
  var detailUrl: String?
  var apiKey = ""
  var channel: String!
  var channelForShow: String!
  var task: NSURLSessionTask?

  @IBOutlet var channelCollectionView: UICollectionView!

  override func viewDidLoad() {

    let baseURL = ""
    getJSON(baseURL)
  }


  //MARK: CollectionView

 func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

    if resultsSearchController.active && resultsSearchController.searchBar.text != ""
    {
      return filteredSearchResults.count
    } else {
      return channelArray.count
    }
  }


 func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
      let cell = collectionView.dequeueReusableCellWithReuseIdentifier("ChannelCell", forIndexPath: indexPath) as! ChannelCell
    let channel: String
    if resultsSearchController.active && resultsSearchController.searchBar.text != "" {
      channel = self.filteredSearchResults[indexPath.row].logo
    } else {
      channel = self.channelArray[indexPath.row].logo
    }
    return cell
  }

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

    var replacedTitle: String?
    if resultsSearchController.active && resultsSearchController.searchBar.text != "" {

      channelForShow = filteredSearchResults[indexPath.row].channelName

      }
    } else {
      channelForShow = self.channelArray[indexPath.row].channelName
      }
    }
    self.dismissSearchBar()
    performSegueWithIdentifier("channelCollectToShowSegue", sender: self)
  }

}

我还有一个用于collectionView Cell的子类：

class ChannelCell : UICollectionViewCell {

  @IBOutlet var channelImageView: UIImageView!

}

Answer 1

您需要将集合视图的数据源设置为控制器。

1）在“界面构建器”中，只需从集合视图拖动到控制器即可。并选择委托和数据源..

2）以编程方式

override func viewDidLoad() {
    super.viewDidLoad()

    channelCollectionView.delegate = self
    channelCollectionView.dataSource = self

   let baseURL = ""
    getJSON(baseURL)
  }

Answer 2

想出来，忘记在故事板中连接委托和数据源。

Answer 3

您是否设置了collectionView的委托和dataSource属性？如果没有，请将viewDidLoad更改为此，以便以编程方式设置这两个属性：

override func viewDidLoad() {
    channelCollectionView.delegate = self
    channelCollectionView.dataSource = self
    let baseURL = ""
    getJSON(baseURL)
}

如果没有设置delegate和dataSource，则collectionView将不知道在哪里调用适当的方法，例如cellForItemAtIndexPath。希望这可以解决您的问题。