ios - TableViews 不适用于 TabBarController Swift

Question

我有一个带有 tableView 的应用程序。我决定用其他 tableViews 添加更多屏幕，所以我以编程方式添加了一个 tabBarController。现在我在这些行上得到一个found nil error:

    tableView.delegate = self
    tableView.dataSource = self

如果我删除它们，tableView 不会加载。你知道我可能做错了什么吗？

我在主 Storyboard上添加了一个 tabBarController 并将其链接到 swift 文件，但它也不起作用。

        class SecondVC: UIViewController,UITableViewDelegate, UITableViewDataSource {

        @IBOutlet weak var tableView: UITableView!

        var SoundsClasss = [SoundsClass]()

        override func viewDidLoad() {
        super.viewDidLoad()

         let p1 = SoundsClass(imageURL: "sound 01", audioURL: "01", videoTitle: "1", duration: 100)
         let p2 = SoundsClass(imageURL: "sound 01", audioURL: "02", videoTitle: "2", duration: 100)

         SoundsClasss.append(p1)
         SoundsClasss.append(p2)

         tableView.delegate = self
         tableView.dataSource = self

         }

TabBarController 的代码。我是否必须在此处更改任何内容以指定该 View 是 tableView？

        class MainTabBarController: UITabBarController {

             override func viewDidLoad() {
              super.viewDidLoad()

                 tabBar.barTintColor = UIColor.white
                 setupTabBar()

                }

             func setupTabBar(){

              let FirstController = UINavigationController(rootViewController: MainVC())
              let SecondController = UINavigationController(rootViewController: SecondVC()) 
              let ThirdController = UINavigationController(rootViewController: ThirdVC())

              viewControllers = [FirstController, SecondController,ThirdController]

              guard let items = tabBar.items else { return }        
              for item in items {
                    item.imageInsets = UIEdgeInsets(top: 4, left: 0, bottom: -4, right: 0)
                   }
                }

             }

Answer 1

在名为 SecondVC 的类中，您有一个 UITableView 实例的导出引用，这意味着您在 Stroyboard 中创建了 TableView ，因此您不能使用应该使用的初始化程序创建 View Controller

UIStoryboard(name: "yourStoryBoardName", bundle: nil).instantiateViewController(withIdentifier: "yourViewcontrollerID")

setupTabBar 函数应该如下所示

 func setupTabBar(){

    let vc1 = UIStoryboard(name: "yourStoryBoardName", bundle: nil).instantiateViewController(withIdentifier: "yourFirstViewcontrollerID")
    let vc2 = UIStoryboard(name: "yourStoryBoardName", bundle: nil).instantiateViewController(withIdentifier: "yourSecondViewcontrollerID")
    let vc3 = UIStoryboard(name: "yourStoryBoardName", bundle: nil).instantiateViewController(withIdentifier: "yourThirdViewcontrollerID")

    let FirstController = UINavigationController(rootViewController: vc1)
    let SecondController = UINavigationController(rootViewController: vc2)
    let ThirdController = UINavigationController(rootViewController: vc3)

    viewControllers = [FirstController, SecondController,ThirdController]

    guard let items = tabBar.items else { return }
    for item in items {
        item.imageInsets = UIEdgeInsets(top: 4, left: 0, bottom: -4, right: 0)
    }
}