如何验证UIAlertController中的TextField？

Z时代
2024-01-10
分类：问答

谁能告诉我如何UITextFields在内验证UIAlertController？

我需要它来防止用户单击“保存”，除非同时输入了两个字段。

到目前为止，这是我的代码：

@IBAction func btnStart(sender: AnyObject) {
    var alert = UIAlertController(title: "New user",
        message: "Add a new user",
        preferredStyle: .Alert)
    let saveAction = UIAlertAction(title: "Save",
        style: .Default) { (action: UIAlertAction!) -> Void in
            self.textFieldName = alert.textFields![0] as UITextField
            self.textFieldEmail = alert.textFields![1] as UITextField
            self.saveUser(self.textFieldName.text, email: self.textFieldEmail.text)
            self.tableView.reloadData()
    }
    saveAction.enabled = false
    let cancelAction = UIAlertAction(title: "Cancel",
        style: .Default) { (action: UIAlertAction!) -> Void in
    }
    alert.addTextFieldWithConfigurationHandler {
        (textFieldName: UITextField!) in
        textFieldName.placeholder = "Enter full name"
    }
    alert.addTextFieldWithConfigurationHandler {
        (textFieldEmail: UITextField!) in
        textFieldEmail.placeholder = "Enter valid email adress"
        textFieldEmail.keyboardType = .EmailAddress
    }
    alert.addAction(saveAction)
    alert.addAction(cancelAction)
    presentViewController(alert,
        animated: true,
        completion: nil)
}

这是我用于验证电子邮件字段的功能：

func isValidEmail(testStr:String) -> Bool {
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"
    if let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx) {
        return emailTest.evaluateWithObject(testStr)
    }
    return false
}

回答：

这可以通过扩展UIAlertViewController：

extension UIAlertController {
    func isValidEmail(_ email: String) -> Bool {
        return email.characters.count > 0 && NSPredicate(format: "self matches %@", "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,64}").evaluate(with: email)
    }
    func isValidPassword(_ password: String) -> Bool {
        return password.characters.count > 4 && password.rangeOfCharacter(from: .whitespacesAndNewlines) == nil
    }
    func textDidChangeInLoginAlert() {
        if let email = textFields?[0].text,
            let password = textFields?[1].text,
            let action = actions.last {
            action.isEnabled = isValidEmail(email) && isValidPassword(password)
        }
    }
}
// ViewController
override func viewDidLoad() {
    super.viewDidLoad()
    let alert = UIAlertController(title: "Please Log In", message: nil, preferredStyle: .alert)
    alert.addTextField {
        $0.placeholder = "Email"
        $0.addTarget(alert, action: #selector(alert.textDidChangeInLoginAlert), for: .editingChanged)
    }
    alert.addTextField {
        $0.placeholder = "Password"
        $0.isSecureTextEntry = true
        $0.addTarget(alert, action: #selector(alert. textDidChangeInLoginAlert), for: .editingChanged)
    }
    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel))
    let loginAction = UIAlertAction(title: "Submit", style: .default) { [unowned self] _ in
        guard let email = alert.textFields?[0].text,
            let password = alert.textFields?[1].text
            else { return } // Should never happen
        // Perform login action
    }
    loginAction.isEnabled = false
    alert.addAction(loginAction)
    present(alert, animated: true)
}