ios - 如何从 tableview 单元格中检索文本字段值

Question

我有一个包含 2 个单元格的表格 View 。两个单元格都有一个文本字段和一个标签。文本字段采用用户名/电子邮件地址和密码的值。

var emailAddress: String?
var password: String?

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier(cellID) as! TextFieldCell

    cell.label.text = loginOptions[indexPath.row]
    cell.textField.placeholder = loginOptions[indexPath.row]

    if indexPath.row == 0 {
        emailAddress = cell.textField.text!
    }
    if indexPath.row == 1 {
        password = cell.textField.text!
    }

    return cell
}   

下面是一个函数，用于检查文本框中是否有任何文本，如果没有，则显示一个警告 Controller ，建议填写所有字段。

func signInButtonTapped() {

    if emailAddress!.isEmpty || password!.isEmpty {

        let alert = UIAlertController(title: "Alert", message: "all fields are required to be filled in", preferredStyle: .Alert)
        let action = UIAlertAction(title: "OK", style: .Default, handler: nil)
        alert.addAction(action)
        self.presentViewController(alert, animated: true, completion: nil)
    }

}

如何从单元格中检索文本字段值以检查它们是否为空？上面的代码不起作用，因为文本字段总是返回空。虽然，希望可以看到我正在努力实现的目标

Answer 1

第一步

在当前类 UITextFieldDelegate 中添加委托(delegate)

class ViewController: UIViewController,UITextFieldDelegate  

第二步

在您的cellForRowAtIndexPath 上调用当前字段的委托(delegate)并添加标签

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier(cellID) as! TextFieldCell
    
    cell.label.text = loginOptions[indexPath.row]
    cell.textField.placeholder = loginOptions[indexPath.row] 
     // add the following lines
     cell.textField.delegate = self
     cell.textField.tag = indexPath.row
     
    
    return cell
}   

第三步

调用 UITextField 委托(delegate)

 func textFieldDidEndEditing(textField: UITextField) {
print("TextField did end editing method called")

if !textField.text.isEmpty // check textfield contains value or not
 {
  if textField.tag == 0
  {
  emailAddress = textField.text!
  }
  else
  {
   password = textField.text!
  }
 }

func textFieldShouldReturn(textField: UITextField) -> Bool {

textField.resignFirstResponder();
return true;
}

  func textFieldDidBeginEditing(textField: UITextField!) {     
     if textField.tag == 0
  {
  emailAddress = ""
  }
  else
  {
   password = ""
  }
}

第四步

如果 emailAddress & password 不包含错误值，则调用你的函数

  func signInButtonTapped() {
    
    if emailAddress!.isEmpty || password!.isEmpty {
        
        let alert = UIAlertController(title: "Alert", message: "all fields are required to be filled in", preferredStyle: .Alert)
        let action = UIAlertAction(title: "OK", style: .Default, handler: nil)
        alert.addAction(action)
        self.presentViewController(alert, animated: true, completion: nil)
    }
else
  {
   // continue your work
  }
    
}