如何为集合视图创建多个数据源？

Question

我有一个tableview有两个单元格和两个嵌入式collectionviews在这些单元格内。当它试图让第二个单元格变形时，我的应用程序不断崩溃。我使用了Ash Furrows教程作为这个项目的基础，我将在这里链接。 Tutorial link

我该如何解决这个问题？这里是一些示例代码。

我有两个不同的细胞，它们各自有这个代码

class TableViewCell: UITableViewCell { 

    @IBOutlet weak var collectionView: UICollectionView! 

    override func awakeFromNib() { 
     super.awakeFromNib() 
     // Initialization code 
    } 

    override func setSelected(_ selected: Bool, animated: Bool) { 
     super.setSelected(selected, animated: animated) 

     // Configure the view for the selected state 
    } 

    func setCollectionViewDataSourceDelegate <D: UICollectionViewDataSource & UICollectionViewDelegate> (dataSourceDelegate: D, forRow row: Int) { 
     collectionView.delegate = dataSourceDelegate 
     collectionView.dataSource = dataSourceDelegate 
     collectionView.tag = row 
     collectionView.reloadData() 
    } 
} 

这自己的阶级是代码的其余部分展示我如何出队我的手机

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) { 
     if indexPath.section == 1 { 
      guard let tableViewCell = cell as? TableViewCell else { 
       return 
      } 

      tableViewCell.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row) 
     } 

     if indexPath.section == 2 { 
      guard let tableViewCell2 = cell as? TableViewCell2 else { 
       return 
      } 
      tableViewCell2.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row) 
     } 


     // we store the offset from here into the dictionary we created above 
     //tableViewCell.collectionViewOffset = storedOffsets[indexPath.row] ?? 0 
    } 

    func tableView(_ tableView: UITableView, didEndDisplaying cell: UITableViewCell, forRowAt indexPath: IndexPath) { 
     guard let tableViewCell = cell as? TableViewCell else { return } 

     storedOffsets[indexPath.row] = tableViewCell.collectionViewOffset 
    } 

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) { 
     print(indexPath) 
    } 
} 

// collectionView inside tableview cell 

extension TabViewController1: UICollectionViewDelegate, UICollectionViewDataSource { 

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { 
     return model[collectionView.tag].count 
    } 

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { 


     if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell", for: indexPath) as? CollectionCell1 { 
      cell.backgroundColor = UIColor.gray 
      return cell 
     } 

     if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell2", for: indexPath) as? CollectionCell2 { 
      cell.backgroundColor = UIColor.purple 
      return cell 
     } 

     return UICollectionViewCell() 
    } 

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { 
     print("Collection view at row \(collectionView.tag) selected index path \(indexPath)") 
    } 
} 

任何帮助将非常感谢！

编辑：这是整个视图控制器类

class TabViewController1: UIViewController, UITableViewDelegate { 

    @IBOutlet private var tableView: UITableView! 

    var model: [[UIColor]] = [] 

    // Here we create a new dictionary to store the offests, corresponding to their rows. 
    var storedOffsets = [Int: CGFloat]() 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     // Do any additional setup after loading the view, typically from a nib. 
     print("tab1") 

     model = generateRandomData() 
     tableView.delegate = self 
    } 

    override func viewWillAppear(_ animated: Bool) { 
     super.viewWillAppear(animated) 
     print("tab 1 viewWillAppear") 
    } 

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

    func generateRandomData() -> [[UIColor]] { 
     let numberOfRows = 20 
     let numberOfItemsPerRow = 15 

     return (0..<numberOfRows).map { _ in 
      return (0..<numberOfItemsPerRow).map { _ in UIColor.randomColor() } 
     } 
    } 
} 

extension TabViewController1: UITableViewDataSource { 

    func numberOfSections(in tableView: UITableView) -> Int { 
     return 5 
    } 

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 
     if section == 3 { 
      return 1 
     } 
     if section == 4 { 
      return 6 
     } else { 
      return 1 
     } 
    } 

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { 

     if indexPath.section == 0 { 
      let cell = tableView.dequeueReusableCell(withIdentifier: "featuredPicture", for: indexPath) as! FeaturedVideoTableViewCell 
      return cell 
     } 

     if indexPath.section == 1 { 
      let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! TableViewCell 
      return cell 
     } 


     if indexPath.section == 2 { 
      let cell = tableView.dequeueReusableCell(withIdentifier: "Cell2", for: indexPath) as! TableViewCell2 
      return cell 
     } 

     if indexPath.section == 3 { 

      let cell = tableView.dequeueReusableCell(withIdentifier: "headerCell", for: indexPath) as! HeaderTableViewCell 
      return cell 
     } 

     if indexPath.section == 4 { 

      let cell = tableView.dequeueReusableCell(withIdentifier: "categoryCell", for: indexPath) as! CategoryTableViewCell 
      return cell 
     } 

     return UITableViewCell() 

    } 

    // titleForHeaderInSection doesnt get called because I implemented the bottom method which is `viewForHeaderInSection`. 
    // I am trying to figure out if we can use both at the same time 
    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? { 

     if section == 0 { 
      return "Featured" 
     } 

     if section == 1 { 
      return "Cool Stuff" 
     } 

     if section == 2 { 
      return "Awesome Stuff" 
     } 

     if section == 3 { 
      return "nothing" 
     } 

     if section == 4 { 
      return "Categories" 
     } 

     return String() 
    } 

    // viewForHeaderInSection 
// func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? { 
//  if section == 3 { 
//   let cell = tableView.dequeueReusableCell(withIdentifier: "headerCell") as! HeaderTableViewCell 
//   return cell 
//  } 
//  return UIView() 
// } 

// func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat { 
//  if section == 3 { 
//   return 50 
//  } 
//  return CGFloat() 
// } 

    func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) { 
     if indexPath.section == 1 { 
      guard let tableViewCell = cell as? TableViewCell else { 
       return 
      } 

      tableViewCell.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row) 
     } 

     if indexPath.section == 2 { 
      guard let tableViewCell2 = cell as? TableViewCell2 else { 
       return 
      } 
      tableViewCell2.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row) 
     } 


     // we store the offset from here into the dictionary we created above 
     //tableViewCell.collectionViewOffset = storedOffsets[indexPath.row] ?? 0 
    } 

    func tableView(_ tableView: UITableView, didEndDisplaying cell: UITableViewCell, forRowAt indexPath: IndexPath) { 
     guard let tableViewCell = cell as? TableViewCell else { return } 

     storedOffsets[indexPath.row] = tableViewCell.collectionViewOffset 
    } 

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat { 
     if indexPath.section == 0 { 
      return 350 
     } 

     if indexPath.section == 1 { 
      return 130 
     } 

     if indexPath.section == 2 { 
      return 200 
     } 

     if indexPath.section == 3 { 
      return 50 
     } 

     if indexPath.section == 4 { 
      return 220 
     } 

     return CGFloat() 
    } 

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) { 
     print(indexPath) 
    } 
} 

// collectionView inside tableview cell 

extension TabViewController1: UICollectionViewDelegate, UICollectionViewDataSource { 

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { 
     return model[collectionView.tag].count 
    } 

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { 

     if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell", for: indexPath) as? CollectionCell1 { 
      cell.backgroundColor = UIColor.gray 
      return cell 
     } 

     if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell2", for: indexPath) as? CollectionCell2 { 
      cell.backgroundColor = UIColor.purple 
      return cell 
     } 

     return UICollectionViewCell() 
    } 


    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { 
     print("Collection view at row \(collectionView.tag) selected index path \(indexPath)") 
    } 
} 

Answer 1

没有看到你在哪里注册你的课程，很难肯定地说，但我怀疑的是，你要回来以外的东西比你的-cellForRow ...或者-cellForItemAt ...方法中的TableViewCell2（或者实际上崩溃的地方）要多。你所有的力量解包（！）都可能导致问题。在崩溃前放置一个断点，然后检查您实际从-dequeueReusableCell调用中返回的内容。