Question

我有两个textFields和一个TableView。 Tableview最初应被禁用（这意味着labels变灰并且cells不可点击）。当两个textFields都具有值时，我希望TableView和tableViewCells是可单击的并且不灰显。到目前为止，我已经向两个textfields添加了目标，以跟踪用户何时进行编辑：

var isUserEditing: Bool = false

func setup() {
        mealItemTextField.addTarget(self, action: #selector(userIsEditing), for: UIControl.Event.editingChanged)
        priceTextField.addTarget(self, action: #selector(userIsEditing), for: UIControl.Event.editingChanged)
    }

@objc func userIsEditing(sender: UITextField) {
        sender.text = sender.text?.trimmingCharacters(in: .whitespaces)
        guard
            let mealtext = mealItemTextField.text, !mealtext.isEmpty,
            let pricetext = priceTextField.text, !pricetext.isEmpty
        else
        {
            isUserEditing = false
            return
        }
        isUserEditing = true
    }

然后，我为UITableViewCell创建了一个扩展名，该扩展名基本上“启用”和“禁用”了tableView（从this线程检索）：

  extension UITableViewCell {
    func enable(on: Bool) {
        for view in contentView.subviews {
            view.isUserInteractionEnabled = on
            view.alpha = on ? 1 : 0.5
        }
    }
}

最后，我在isUserEditing中实现了该方法以及变量viewForHeaderInSection：

func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
    let userModel = Data.userModels[section]
    let cell = tableView.dequeueReusableCell(withIdentifier: "nameCell") as! NameHeaderTableViewCell
    cell.setup(model: userModel)
    cell.enable(on: false)
    if isUserEditing == true {
        cell.enable(on: true)
    }
    return cell.contentView
}

在加载视图时，tableView会显示为“禁用”，但是当我开始输入textFields中的一个或两个时，它将保持禁用状态。因此很明显viewForHeaderInSection不会重新加载或再次执行。

有什么办法可以做到这一点？我可以实时运行viewForHeaderInSection并自动更新吗？感谢您的任何帮助，谢谢！

This should be the initial view when there is no text in the textField

This should be the view after there is some text in both textFields

Answer 1

tableView.reloadData（）丢失，因为未重新加载该表视图。

@objc func userIsEditing(sender: UITextField) {
       sender.text = sender.text?.trimmingCharacters(in: .whitespaces)
       guard
           let mealtext = mealItemTextField.text, !mealtext.isEmpty,
           let pricetext = priceTextField.text, !pricetext.isEmpty
       else
       {
           isUserEditing = false
       tableView.reloadData() // reload table view here
           return
       }
       isUserEditing = true
    tableView.reloadData() // reload table view here
   }

Answer 2

如果您希望在出现键盘时启用tableView并且文本字段为空，则可以通过通知进行检查；

在您的ViewController类中：

        override func viewDidLoad() {
             super.viewDidLoad()
             yourTableView.isUserInteractionEnabled = false

         // check notifications if keyboard shown or not
            NotificationCenter.default.addObserver(self, selector: #selector(showKeyboard), name: UIResponder.keyboardWillShowNotification, object: nil)     
            NotificationCenter.default.addObserver(self, selector: #selector(hideKeyboard), name: UIResponder.keyboardWillHideNotification, object: nil)

         // if your textFields out of your tableview
              yourTextField1.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: .editingChanged)
                yourTextField2.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: .editingChanged)

                }


 @objc func textFieldDidChange(textField: UITextField){

     self.yourTableView.isUserInteractionEnabled = true
     print("Text changed")

  }

  // show keyboard function
  @objc func showKeyboard(notification: NSNotification){

  // You can disable your tableview or your cells in this case i just disable tableview.

     yourTableView.isUserInteractionEnabled = true
     print("keyboard appeared")
   }

   // this part is up to how you want to implement. If you want to keep tableview active after textField edited don't use this method

  @objc func hideKeyboard(notification: NSNotification){

   // You can disable your tableview or your cells
      yourTableView.isUserInteractionEnabled = false
      print("keyboard disappeared")
   }

   func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
   let userModel = Data.userModels[section]
   let cell = tableView.dequeueReusableCell(withIdentifier: "nameCell") as! NameHeaderTableViewCell

        // if your text Fields inside tableView tracking you textfield changes (in this case you couldn't disable tableView initially) 

   cell.yourTextField1.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: .editingChanged)
   cell.yourTextField2.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: .editingChanged)
                return cell.contentView
   }

我希望这能解决您的问题，祝您好运。

当文本字段中有文本时，如何启用UITableView

2 个答案: