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ios - 使用“执行segue”传递错误返回nil？

问题描述

我试图在应用程序用户以错误的方式登录或注册时向他们显示错误，例如密码需要 6 个字符，所以如果他/她输入 4 或 5，它应该会给他带来错误，但它只在 Xcode 中打印并且总是 nil在应用程序中（我是新来的，网站告诉我图片太大而无法上传，所以我记下来了）。有人可以帮我弄清楚这里的代码有什么问题吗？谢谢！！

// This is the code for the first viewcontroller where I try to pass the error to the ErrorViewController

 if let email = emailTextfield.text, let password = passwordTextfield.text{
    Auth.auth().signIn(withEmail: email, password: password) { [weak self] authResult, error in 
     if let e = error {
        print(e)
        self!.performSegue(withIdentifier: "GoToError", sender: self)
       func prepare(for segue: UIStoryboardSegue, sender: Any?) {
       if segue.identifier == "GoToError" {
           let GoTo = segue.destination as! ErrorViewController
        GoTo.errorText = "\(e.localizedDescription)"}
       }
     }else{
        self!.performSegue(withIdentifier:K.loginSegue, sender: self)
        }

    }
    }

// This is the code of the ErrorViewController where It should catch the error and pass it to the ErrorText label and get printed to the app screen 

errorText: String?   

@IBOutlet weak var ViewMessage: UIView!
@IBOutlet weak var ErrorText: UILabel!
override func viewDidLoad() {
    super.viewDidLoad()

     ViewMessage.layer.cornerRadius = ViewMessage.frame.size.height / 4



    if errorText != nil {
    ErrorText.text = errorText
    }else{

// The string below is what gets printed because the error is always nil

        ErrorText.text = "make sure your password is at least 6 characters"

标签： iosswiftxcodeerror-handlingsegue

解决方案

原因是prepare(for segue必须在类的顶层（与 同级viewDidLoad）上实现。

并且请以小写字母开头命名变量、函数和枚举案例。

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