iOS 文本字段DidBeginEditing

Question

我正在寻找有关我尝试使用的扩展的一些帮助，它是一个登录页面，通过我的 statusLabel.text 发出错误，例如，如果他们输入不正确的密码，statusLabel.text 将显示“电子邮件地址不正确，请重试”

这是我的登录部分

@IBAction func login(_ sender: Any) {

    self.userName.resignFirstResponder()
    self.password.resignFirstResponder()
    self.repeatPassword.resignFirstResponder()
    self.passwordsStack.resignFirstResponder()


    self.progress.startAnimating()
    switch self.currentLoginType {

    case .login:

        let email = self.userName.text
        let password = self.password.text

        FirebaseManager.login(email: email!, password: password!, completion: { (status: Bool, error: Error?) in

            if status && error == nil {
                if FirebaseManager.isEmailVerified {

                    self.dismiss(animated: true, completion: nil)
                    print (error?.localizedDescription ?? "")

                    let storyboard = UIStoryboard(name: "Main", bundle: nil)
                    let LoginVC = storyboard.instantiateViewController(withIdentifier: "ReavealVC") as! SWRevealViewController
                    let appDelegate = UIApplication.shared.delegate as! AppDelegate
                    appDelegate.window?.rootViewController = LoginVC

                } else {

                    DispatchQueue.main.async {
                        self.statusLabel.text = "Your email is not verified. Please check your email"
                        self.progress.stopAnimating()
                        print ("have we stopped at email not verified")
                        self.clearLoginTextFields()
                    }
                }
            } else {

                DispatchQueue.main.async {
                    self.progress.stopAnimating()
                    self.statusLabel.text = FirebaseManager.StringFromError(error: error)
                    print("have we stopped at email after its not verified")
                    self.clearLoginTextFields()
                }

            }

        })


    case .signup:

        if self.password.text == self.repeatPassword.text{

            let email = self.userName.text
            let password = self.password.text

            FirebaseManager.LinkWithEmailAndPassword(email: email!, password: password!, completion: { (status: Bool, error: Error?) in

                if status && error == nil {

                    self.dismiss(animated: true, completion: nil)

                    self.progress.stopAnimating()
                    self.statusLabel.text = "Email verification sent, please check you inbox"
                    print(error?.localizedDescription ?? "")

                } else {

                    DispatchQueue.main.async {
                        self.progress.stopAnimating()
                        self.statusLabel.text = FirebaseManager.StringFromError(error: error)

                    }
                }
            })
            self.view.endEditing(true)
            clearLoginTextFields()

        }else{
            self.progress.stopAnimating()
            self.statusLabel.text = "Passwords do not match, please try again!"
        }

    case .forgotPassword:

        FirebaseManager.sendPasswordReset(email: self.userName.text!, completion: { (status:Bool) in

            DispatchQueue.main.async {
                self.progress.stopAnimating()
                self.statusLabel.text = status ? "Reset password sent" : "Error sending reset password"
            }
        })

        break
    }

}

还有我的扩展

extension LoginViewController: UITextFieldDelegate {

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

        return true
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {

        textField.resignFirstResponder()

        return true
    }

    func textFieldDidEndEditing(_ textField: UITextField) {

        textField.resignFirstResponder()

    }

    func textFieldDidBeginEditing(_ textField: UITextField) {

        statusLabel.text = ""
    }
}

一旦用户开始再次输入其凭据，我希望状态标签恢复为“”，但看起来我的 textFieldDidBeginEditing 没有被调用

Answer 1

您需要设置 UITextFields 的委托(delegate)。

userName.delegate = self
password.delegate = self

我假设两个文本字段都位于 LoginViewController 中。

除了这种方法之外，您可以不使用委托(delegate)的东西并执行以下操作:

userName.addTarget(self, action: #selector(textChanged(_:)), for: .editingChanged)

和

func textChanged(textField: UITextField) {

}

在设置“”之前，您可能需要检查是否显示消息:“电子邮件不正确，请重试”。