TableViewCell中的Swift 3.0文本字段未显示

我试图使用自定义单元格在tableview上显示textfield。我认为我已经正确设置了委托协议,但加载时,tableview不会显示textfield。我在customcell中添加了一个textfield,将类设置为customcell,并将标识符更改为“Cell”,但我不确定还缺少什么。

带有tableview的视图控制器:

@IBOutlet weak var tableView: UITableView! 


 override func viewDidLoad() {
    super.viewDidLoad()

    tableView.delegate = self
    tableView.dataSource = self
}

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

}

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

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    return data.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! CustomCell
    cell.cellDelegate = self
    cell.contentView.bringSubview(toFront: cell.textField)
    cell.textField.delegate = self as? UITextFieldDelegate
    cell.textField.text = "Test"

    return cell
}

func didPressTextField(indexPath: IndexPath) {
    print("textfield was tapped")
}

protocol CustomCellDelegate : class {
    func didPressTextField(indexPath: IndexPath)
}

class CustomCell: UITableViewCell {

    weak var cellDelegate: CustomCellDelegate?
    var indexPath: IndexPath!

    override func awakeFromNib() {
        super.awakeFromNib()
        self.cellDelegate = nil
        // Initialization code
    }

    @IBOutlet weak var textField: UITextField!
    @IBAction func textFieldWasTapped(_ sender: UITextField) {
        self.cellDelegate?.didPressTextField(indexPath: indexPath)
    }