Swift 将多个对象发送到视图控制器

问题描述

我正在尝试将多个对象从我的初始视图控制器发送到我的 Username VC.这是我的控制器的 segue 代码:当我添加代码以发送第二个对象 termreport 时，问题就出现了.如果我删除 termsM 和作业，它会像往常一样发送学生，但我还需要发送 termReport 对象.我该如何解决这个问题?

I am trying to send multiple objects from my initial view controller to my Username VC. Here is the segue code from my controllers: The issue comes when I add in the code to send the second object, termreport. If I delete the termsM and the assignment, it send the students as usually, but I also need to send the termReport object. How would I fix this?

视图控制器:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard let students = sender as AnyObject as? [Student]
    else { return }
    guard let termsM = sender as AnyObject as? [TermReport] //How would I send both objects?
    else { return }
    if let secondVC = segue.destination as? UsernameVC {
        secondVC.students = students
        secondVC.userWebView = webView
        secondVC.terms = termsM // not sending
    }
    let gradeResponse = try Parser(innerHTML)
    self.performSegue(withIdentifier: "ShowStudents", sender: gradeResponse.students)
    self.performSegue(withIdentifier: "ShowStudents", sender: gradeResponse.termReports) //how would I send both variables?

用户名VC:

var terms: [TermReport]!
override func viewDidLoad() {
    print("TERM \(terms[0].grades[3])")//returns found nil optional ERROR
}

推荐答案

您必须使用 segue 将要发送到另一个 ViewController 的所有变量包含到单个对象中(可以是一个集合).您可以创建一个具有 [Student] 和 [TermReport] 类型属性的自定义类/结构，或者将它们放入本机集合(元组或字典)中.

You have to include all of the variables you want to send to another ViewController using a segue into a single object (which can be a collection as well). You either create a custom class/struct that has properties with type [Student] and [TermReport] or put these into a native collection (Tuple or Dictionary).

创建自定义结构:

struct TermData {
   var students = [Student]()
   var termReports = [TermReport]()
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard let segueData = sender as? TermData
    else { return }
    if let secondVC = segue.destination as? UsernameVC {
        secondVC.students = segueData.students
        secondVC.userWebView = webView
        secondVC.terms = segueData.termReports
        }
}

let gradeResponse = try Parser(innerHTML)
let termData = TermData(students: gradeResponse.students, termReports: gradeResponse.termReports)
self.performSegue(withIdentifier: "ShowStudents", sender: termData)

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