ios - 如何从 UIViewController 获取 CLASS

Question

我有 UIViewController 以及如何将 UIViewController 转换为 Class.swift。类已初始化...

MainController.staticInstance.viewControllers?[1] as! Destination

MainController是扩展UITabBarController的类。我想从 UITabBar 获取子 Controller 并将其转换为 Class which Parent。

明显的例子:

class MainController: UITabBarController {
override func viewDidLoad() {
  (self.viewControllers?[1] as! Destination).itsMyFunction();
 }
}

最大细节:

1 类

class First: UIViewController {
 func itsMyFunction() {
  print("Hello world!")
 }
}

这是我附加到 Storyboard中的类(class)!

2级

class MainController: UITabBarController {
     func override viewDidLoad() {
       // Here I set index UITabBar ITEM which attach to MAIN UiTabBarController
       self.selectedIndex = 0
       // NOW I want to get INSTANCE CLASS First
       (self.viewControllers?[1] as! First).itsMyFunction();
     }
}

Answer 1

您能按照这个设置示例进行操作吗？

class TabBarViewController: UITabBarController {

let firstVC = First()
let secondVC = SecondViewController()

override func viewDidLoad() {
    super.viewDidLoad()

    firstVC.tabBarItem = UITabBarItem(tabBarSystemItem: .search, tag: 0)
    secondVC.tabBarItem = UITabBarItem(tabBarSystemItem: .more, tag: 1)

    let tabBarList = [firstVC, secondVC]

    viewControllers = tabBarList

    if let destination = viewControllers?.first as? First {
      destination.itsMyFunction()
    }
  }
}

您似乎无法获取 controller 的 Class 实例，因为根据您发布的代码，您的 viewControllers 数组为空。让我知道它是否有效。