具有自定义数据源的UITableViewController不显示单元格

Question

I currently have a UITableViewController that sets up a custom data source in its init function:

class BookmarkTableViewController: UITableViewController {
  var date: Date

  // MARK: - Init
  init(date: Date, fetchAtLoad: Bool) {
    self.date = date
    super.init(style: .plain)
    self.tableView.dataSource = BookmarkDataSource(date: date)
    self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
  }

// ...
}

The custom data source is as follows:

class BookmarkDataSource: NSObject {
  let date: Date

  init(date: Date) {
    self.date = date
    super.init()
  }
}

// MARK: - UITableViewDataSource
extension BookmarkDataSource: UITableViewDataSource {
  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 3
  }

  func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = UITableViewCell()
    cell.textLabel?.text = "Test content"

    return cell
  }
}

However when I run on the simulator or on a device nothing shows up in the table view. Does anyone know what I'm missing?

Note: I'm using Xcode 8.0 Beta and Swift 3.

Answer 1

You need to store a strong reference to your BookmarkDataSource object. The dataSource of tableView becomes nil with the code you posted.

class BookmarkTableViewController: UITableViewController {
    var date: Date
    var dataSource:BookmarkDataSource

    // MARK: - Init
    init(date: Date, fetchAtLoad: Bool) {
        self.date = date
        super.init(style: .plain)
        dataSource = BookmarkDataSource(date: date)
        self.tableView.dataSource = dataSource
        self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
    }

    // ...
}

Answer 2

I think your cells aren't being properly instantiated.

Try replacing

let cell = UITableViewCell()

with

let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)