ios - 当数据源和委托(delegate)与 View Controller 分离时，如何将 TableView 的单击项目发送到其他 View Controller

Question

我是 iOS 的初学者，来自 android 背景，刚刚了解了表格 View (对我来说是 Android ListView)。我正在尝试将数据源和委托(delegate)与 View Controller 分开。我找到了一些关于如何执行此操作的教程，但一直在弄清楚如何将单击的项目发送到另一个 View Controller 。代码如下:

class PictureTableViewController: UIViewController {


    @IBOutlet weak var pictureTableView: UITableView!

    private let picsDataSource: PicturesDataSource

    required init?(coder aDecoder: NSCoder) {
        self.picsDataSource = PicturesDataSource()
        super.init(coder: aDecoder)
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        pictureTableView.dataSource = picsDataSource
        pictureTableView.reloadData()
        pictureTableView.delegate = picsDataSource
    }
}

class PicturesDataSource: NSObject, UITableViewDataSource, UITableViewDelegate{

    private var pictureModels = [PictureModel]()

    override init(){
        let picModelsDataController = PictureModelsDataController()
        pictureModels = picModelsDataController.pictureModels
    }


    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return pictureModels.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: String(describing: PictureCell.self)) as! PictureCell

        let picModel = pictureModels[indexPath.row]
        cell.pictureName = picModel.pictureName
        cell.imageItem = picModel.imageItem

        return cell
    }

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


        //1 - try loading the "Detail" view controller and typecasting it to be DetailViewController
        if let detailViewController = storyboard.instantiateViewController(withIdentifier: "PictureDetailView") as? PictureDetailViewController {

            //2 - success! set its selecteImage property
            detailViewController.selectedImgName = pictureModels[indexPath.row].pictureName

            //3 - now push it onto the navigation controller
            navigationController?.pushViewController(detailViewController, animated: true)
        }
    }

}     

错误:func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){ }。 由于“storyboard”和“navigationController”在 PicturesDataSource 类中不可用，我如何将点击的项目(图片名称)发送到 DetailsViewController

有关于分离数据源和委托(delegate)的 StackOverflow 答案，但没有解决我的问题。

Using: Xcode 8.3 beta 6

Answer 1

您可以在 TableView 事件处理程序中包含对主视图 Controller 的引用。下面是我从您的示例中派生的 Playground 代码:

import UIKit

// MARK: - Model

struct Picture {
  let title: String
  let image: UIImage
}

struct PictureModelsDataSource {
  let pictures = [
    Picture(title: "exampleTitle", image: UIImage(named: "exampleImage")!),
    Picture(title: "exampleTitle", image: UIImage(named: "exampleImage")!)
  ]
}

// MARK - View

class PictureCell: UITableViewCell {
  @IBOutlet weak var pictureTitleLabel: UILabel!
  @IBOutlet weak var pictureImage: UIImageView!
}

// MARK: - Controller

class PictureTableViewController: UIViewController {

  // MARK: - Properties

  @IBOutlet weak var pictureTableView: UITableView!

  private var pictureListController: PictureListController?

  // MARK: - View lifecycle

  override func viewDidLoad() {
    super.viewDidLoad()
    pictureListController = PictureListController()
    pictureListController?.viewController = self
    pictureTableView.dataSource = pictureListController
    pictureTableView.delegate = pictureListController
    pictureTableView.reloadData()
  }
}

class PictureDetailViewController: UIViewController {
  var selectedPictureTitle: String?
}

class PictureListController: NSObject, UITableViewDataSource, UITableViewDelegate {

  // MARK: - Properties

  weak var viewController: PictureTableViewController?

  private let pictures: [Picture] = {
    let pictureModelsDataSource = PictureModelsDataSource()
    return pictureModelsDataSource.pictures
  }()

  // MARK: - View setup

  func numberOfSections(in tableView: UITableView) -> Int {
    return 1
  }

  // MARK: - Event handling

  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return pictures.count
  }

  func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    guard let cell = tableView.dequeueReusableCell(withIdentifier: String(describing: PictureCell.self)) as? PictureCell else {
      return UITableViewCell()
    }

    let picture = pictures[indexPath.row]
    cell.pictureTitleLabel.text = picture.title
    cell.pictureImage.image = picture.image

    return cell
  }

  func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let pictureTitle = pictures[indexPath.row].title
    let storyboard = UIStoryboard(name: "exampleStoryboard", bundle: nil)
    if let pictureDetailViewController = storyboard.instantiateViewController(withIdentifier: "PictureDetailView") as? PictureDetailViewController {
      pictureDetailViewController.selectedPictureTitle = pictureTitle
      viewController?.navigationController?.pushViewController(pictureDetailViewController, animated: true)
    }
  }
}