以编程方式从子视图快速返回按键事件

Question

我是 swift 新手，不使用故事板就可以创建我的应用程序。我创建了 logincontroller 并将 loginview 附加到它。当有人完成电子邮件和密码文本字段并从键盘按返回键时，我想检测事件以便处理用户的登录请求。

这是我的代码。

import UIKit

class LoginController: UIViewController {

 var loginView: LoginView!

 override func viewDidLoad() {
    super.viewDidLoad()
    setupView()
 }

func setupView() {
    let mainView = LoginView(frame: self.view.frame)
    self.loginView = mainView 
    self.view.addSubview(loginView)
}

以及 LoginView.swift 的代码

import UIKit

class LoginView: UIView {

override init(frame: CGRect) {
    super.init(frame: frame)
    setup()
}

func setup() {

    backgroundColor = .white
    let stackView = createStackView(views: [emailTextField,passwordTextField])
    addSubview(stackView)

    //autolayout constraints here

}

let emailTextField: UITextField = {
    let tf = UITextField(placeHolder: "Email")
    return tf
}()

let passwordTextField: UITextField = {
    let tf = UITextField(placeHolder: "Password")
    tf.isSecureTextEntry = true
    tf.returnKeyType = UIReturnKeyType.send
    return tf
}()

Answer 1

只需将此添加到setup 方法

func setup() {
    backgroundColor = .white
    let stackView = createStackView(views: [emailTextField,passwordTextField])
    addSubview(stackView)
    emailTextField.delegate = self // This
    passwordTextField.delegate = self // And this
}

然后将其添加到您的 LoginView 类下方

extension LoginView: UITextFieldDelegate {
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if textField == passwordTextField {
             passwordTextField.resignFirstResponder()
             doWhatYouWantTo() // eg. do your login
        } else {
             passwordTextField.becomeFirstResponder()
        }
        return false
    }
}

扩展答案-

class LoginController: UIViewController {
    var loginView: LoginView!

    override func viewDidLoad() {
        super.viewDidLoad()
        setupView()
    }

    func setupView() {
        let mainView = LoginView(frame: self.view.frame)
        self.loginView = mainView
        self.loginView.delegate = self
        self.view.addSubview(loginView)
    }
}

extension LoginController: LoginViewDelegate{
    func userWantsToLoginWith(userName: String?, password: String?) {
        // Now you have both userName and password here
    }
}

protocol LoginViewDelegate: class {
    func userWantsToLoginWith(userName: String?, password: String?)
}

class LoginView: UIView {
    var delegate: LoginViewDelegate?

    let emailTextField: UITextField = {
        let tf = UITextField(placeHolder: "Email")
        return tf
    }()

    let passwordTextField: UITextField = {
        let tf = UITextField(placeHolder: "Password")
        tf.isSecureTextEntry = true
        tf.returnKeyType = UIReturnKeyType.send
        return tf
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

    func setup() {
        backgroundColor = .white
        let stackView = createStackView(views: [emailTextField, passwordTextField])
        addSubview(stackView)
        //autolayout constraints here
    }
}

extension LoginView: UITextFieldDelegate {
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if textField == passwordTextField {
            passwordTextField.resignFirstResponder()
            delegate?.userWantsToLoginWith(userName: emailTextField.text, password: passwordTextField.text)
        } else {
            passwordTextField.becomeFirstResponder()
        }
        return false
    }
}