swift - 如何在 swift 中使用 userdefaults 进行登录/注册和注销导航？

Question

我有 scenedelegate、appdelegate、signinVC、signupVC 和 homeVC

视图控制器流程如下

      UINavigationController(initialVC) ->SigninVC (signin and signup buttons) -> homeVC(logoutBtn)

我需要当我登录或注册时我需要移动 homeVC，如果我注销我需要回到 loginVC，我需要用户自动登录，直到我点击 homeVC 中的注销按钮

在注册VC中：

  class RegisterViewController: UIViewController {
@IBOutlet weak var firstNameTextfield: UITextField!
@IBOutlet weak var lastNameTextfield: UITextField!
@IBOutlet weak var emailTextfield: UITextField!
@IBOutlet weak var passwordTextfield: UITextField!

@IBAction func registerBtnClicked(_ sender: Any) {
    
    if firstNameTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter first name")

    }
    else if lastNameTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter last name")

    }else if emailTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter email")

    }else if passwordTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter password")

    }
    else{
        UserDefaults.standard.set(firstNameTextfield.text, forKey: "userName")
                UserDefaults.standard.set(lastNameTextfield.text, forKey: "lastName")
                UserDefaults.standard.set(emailTextfield.text, forKey: "email")
                UserDefaults.standard.set(passwordTextfield.text, forKey: "userPassword")
        
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let vc = storyboard.instantiateViewController(withIdentifier: "HomeViewController") as! HomeViewController
         navigationController?.pushViewController(vc, animated: true)
        
    }
}

在signinVC中：

class ViewController: UIViewController {
@IBOutlet weak var userNameTextfield: UITextField!
@IBOutlet weak var passwordTextfield: UITextField!
@IBAction func loginBtnClicked(_ sender: Any) {
    
    let uName = UserDefaults.standard.string(forKey: "userName")
    
    let uPassword = UserDefaults.standard.string(forKey: "userPassword")

    if userNameTextfield.text == uName && passwordTextfield.text == uPassword{
        UserDefaults.standard.set(true, forKey: "USER_LOGIN")

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let vc = storyboard.instantiateViewController(withIdentifier: "HomeViewController") as! HomeViewController
         navigationController?.pushViewController(vc, animated: true)
    }
    else{
        showAlert(title: "LogIn", message: "please enter username and password")
    }
}

@IBAction func registerBtnClicked(_ sender: Any) {
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "RegisterViewController") as! RegisterViewController
     navigationController?.pushViewController(vc, animated: true)
}
}

在 homeVC 中：

class HomeViewController: UIViewController {

@IBAction func logoutBtnClicked(_ sender: Any) {
    UserDefaults.standard.set(false, forKey: "USER_LOGIN") //logging session off

    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "ViewController") as! ViewController
     navigationController?.pushViewController(vc, animated: true)
}
}

使用上面的代码只有最近注册的用户才能登录并且自动登录不起作用

如何登录所有注册用户以及如何自动登录到主页，直到我点击注销按钮..请提供代码帮助

标签： swiftuinavigationcontrollerrootviewcontroller

Answer 1

在 signinVC 中在 viewDidLoad 中添加以下行

if UserDefaults.standard.bool(forKey: "USER_LOGIN"){
            //navigate to home page
            DispatchQueue.main.async {
                let storyboard = UIStoryboard(name: "Main", bundle: nil)
                let vc = storyboard.instantiateViewController(withIdentifier: "HomeViewController") as! HomeViewController
                navigationController?.pushViewController(vc, animated: true)
            }
        }

修改signupVC如下

class RegisterViewController: UIViewController {
@IBOutlet weak var firstNameTextfield: UITextField!
@IBOutlet weak var lastNameTextfield: UITextField!
@IBOutlet weak var emailTextfield: UITextField!
@IBOutlet weak var passwordTextfield: UITextField!

    
var userDict : Dictionary<String,UserData>?
    
@IBAction func registerBtnClicked(_ sender: Any) {
    
    if firstNameTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter first name")

    }
    else if lastNameTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter last name")

    }else if emailTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter email")

    }else if passwordTextfield.text?.isEmpty == true{
        self.showAlert(title: "Registration", message: "please enter password")

    }
    else{
        self.userDict = UserDefaults.standard.dictionary(forKey: "UserList") as! Dictionary<String, RegisterViewController.UserData>
        
        let userData = UserData(userName: firstNameTextfield.text, lastName: lastNameTextfield.text, email: emailTextfield.text, userPassword: passwordTextfield.text)
        self.userDict[firstNameTextfield.text] = userData
        
        UserDefaults.standard.setValue(self.userDict, forKey: "UserList")
        
        DispatchQueue.main.async {
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let vc = storyboard.instantiateViewController(withIdentifier: "HomeViewController") as! HomeViewController
             navigationController?.pushViewController(vc, animated: true)
        }
        
        
    }
}

struct UserData {
    var userName : String
    var lastName : String
    var email : String
    var userPassword : String
}

最后修改 loginBtnClicked 方法如下

@IBAction func loginBtnClicked(_ sender: Any) {
    
     let userDict = UserDefaults.standard.dictionary(forKey: "UserList") as! Dictionary<String, UserData>
    
    guard let usrData = userDict[userNameTextfield.text] as! UserData else {
        // no user registered with this user name
        return
    }
    
    if usrData.userPassword == passwordTextfield.text {
        // login successfull
        UserDefaults.standard.set(true, forKey: "USER_LOGIN")
        DispatchQueue.main.async {
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let vc = storyboard.instantiateViewController(withIdentifier: "HomeViewController") as! HomeViewController
             navigationController?.pushViewController(vc, animated: true)
        }
             
    }else{
        //login failed
        showAlert(title: "LogIn", message: "please enter username and password")
    }
    
}