swift - 从 UIAlertController 中的 UITextField 获取字符串 (Swift)

Question

我这几天一直在抓狂，确实需要一些帮助。

我有一个如下定义的属性:

@objcMembers class Account: Object {

    dynamic var name = ""

当我用文字加载 .name 时，即，

            let newAccount = Account()
//            newAccount.name = self.accountTextField.text!
            newAccount.name = "John Brown"
            newAccount.isCurrent = true
            newAccount.highWaterBalance = 0.0

我明白了:

acct.name is John Brown
acct.highWaterBalance is 0.0
acct.isCurrent is true

但是，当我在 self.accountTextField 中输入“John Brown”并使用以下代码时:

            let newAccount = Account()
            newAccount.name = self.accountTextField.text!
//            newAccount.name = "John Brown"
            newAccount.isCurrent = true
            newAccount.highWaterBalance = 0.0

我明白了:

acct.name is 
acct.highWaterBalance is 0.0
acct.isCurrent is true

我已经搜索了所有内容，并认为我已经解决了 @rmaddy 对 this question 的贡献.

我认为我做得对，但我仍然从 textField 中得到空白。

任何帮助将不胜感激!

编辑 1:

这段代码:

        print("Johnny B Goode\n")
        print ("\(self.accountTextField.text!)")
        print("Johnny B Bad\n")

打印此结果:

Johnny B Goode


Johnny B Bad

编辑2:

为了完全清楚起见，也许我应该之前提到过这一点，这里是生成警报的 IBAction 代码，其中 self.accountTextField.text 位于:

   @IBAction func addAccountButton(_ sender: Any) {

        // Pop alert to add new account



        let addAcctAlert = UIAlertController(title: "Create New Account", message: "Please name your new account", preferredStyle: UIAlertControllerStyle.alert)

        addAcctAlert.addTextField { (accountTextField) in
            accountTextField.placeholder = "Enter new account name"
            accountTextField.keyboardType = .`default`
        }

        addAcctAlert.addAction(UIAlertAction(title: "Continue", style: UIAlertActionStyle.destructive, handler: { action in

            // Create new Account with name, balance, isCurrent, save to disk
            print("Johnny B Goode\n")
            print ("\(self.accountTextField.text!)")
            print("Johnny B Bad\n")

            let newAccount = Account()
            newAccount.name = self.accountTextField.text!
//            newAccount.name = "John Brown"
            newAccount.isCurrent = true
            newAccount.highWaterBalance = 0.0

            self.addCreatedAccount(thisAccount: newAccount)
        }
        ))

        addAcctAlert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel, handler: nil))
        self.present(addAcctAlert, animated: true, completion: nil)
    }

确实，无论我在 textField 中输入什么内容，它都不会产生任何结果。这可能吗？

Answer 1

如果您尝试从添加到 UIAlertController 的帐号文本字段中获取值，那么您应该这样做。

newAccount.name = addAcctAlert.textFields?.first?.text ?? "I haven't typed anything in alert controller's text field"

或

if let accountName: String = addAcctAlert.textFields?.first?.text {
    newAccount.name = accountName
}