如何在类B中的类A的函数体内访问变量的值？

Question

基本上我想在函数（类SignUpPage.swift）中使用变量'userID'来将它称为HERE它在ViewController.swift类中。

我曾试图使用户ID全局变量

ref.child（ “用户”）子（这里）.setValue。（[userLN “名”：userFN， “姓”]）也是，但这是不行的。 这里是整个代码：

class SignUpPage: UIViewController { 

var ref: FIRDatabaseReference! 

override func viewDidLoad() { 
    super.viewDidLoad() 

    ref = FIRDatabase.database().reference() 

} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
} 
@IBOutlet weak var emailField: UITextField! 
@IBOutlet weak var passwordField: UITextField! 



@IBAction func signUpButton(_ sender: Any) { 


    FIRAuth.auth()?.createUser(withEmail: emailField.text!, password: passwordField.text!, completion: { (user, error) in 


     if error != nil{ 

      print(error!.localizedDescription) 
     } 

我想在ViewController.swift类中使用这个变量（用户ID），这样我可以节省名字，姓氏，EMAILID和密码相同令牌下。

 let userID = user!.uid 

     let userEmail = self.emailField.text! 
     let userPassword = self.passwordField.text! 

     self.ref.child("Users").child(userID).setValue(["User Email": userEmail, "User Password": userPassword]) 
    }) 

} 

}

ViewController.swift类

class ViewController: UIViewController { 

var ref: FIRDatabaseReference! 

var ID = String() 

override func viewDidLoad() { 
    super.viewDidLoad() 

    ref = FIRDatabase.database().reference() 

} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
} 
@IBOutlet weak var fnField: UITextField! 
@IBOutlet weak var lnField: UITextField! 

@IBAction func nextButton(_ sender: Any) { 



    let userFN: String = fnField.text! 
    let userLN: String = lnField.text! 

    ref.child("Users").child(**HERE**).setValue(["First Name": userFN, "Last Name": userLN]) 

} 

}

Answer 1

据我所知，这是基本身份验证逻辑，那么你为什么不保存用户id在UserDefaults，

let userID = user!.uid 
let userDefaults = UserDefaults.standard 
userDefaults.set(userID, forKey: "userID") 

比任何地方，当你想存储的用户ID，

let userDefaults = UserDefaults.standard 
let userID = userDefaults.string(forKey: "userID") 
ref.child("Users").child(userID).setValue(["First Name": userFN, "Last Name": userLN])