Question

我正在尝试从初始视图控制器向我的Username VC发送多个对象。这是来自我的控制器的segue代码：当我添加代码以发送第二个对象termreport时，会出现问题。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？

ViewControler ：

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?

UsernameVC ：

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

Answer 1

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（也可以是一个集合）中。您可以创建具有类型[Student]和[TermReport]的属性的自定义类/结构，也可以将它们放入本机集合（元组或字典）。

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)

Swift将多个对象发送到View Controller

1 个答案: