ios - 在 ViewController Swift 3 中添加 UITabBar(不实现 UITabBarController)

Question

我成功地向我的 UIViewController 添加了一个 UITabBar。但是，当标签被选中时，我无法切换 View Controller 。我使用了以下方法:

public func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {

    switch item.tag {
    case 1 :
          var storyboard = UIStoryboard(name: "Main", bundle: nil)
            let viewController = storyboard.instantiateViewController(withIdentifier: "HardwareViewController") as! HardwareViewController
            self.addChildViewController(viewController)
        break
    case 2 :

 self.performSegue(withIdentifier : IDENTIFIER_SEGUE_SYSTEMVC, sender : nil)
        break
    case 3 :

        var storyboard = UIStoryboard(name: "Main", bundle: nil)
        let viewController = storyboard.instantiateViewController(withIdentifier: "SystemViewController") as! SystemViewController
        self.view.insertSubview(viewController.view!, belowSubview: self.tabBar)
        break
    case 4 :

        var storyboard = UIStoryboard(name: "Main", bundle: nil)
        let viewController = storyboard.instantiateViewController(withIdentifier: "HardwareViewController") as! HardwareViewController
      self.view.insertSubview(viewController.view!, belowSubview: self.tabBar)
        break
    case 5 :

        var storyboard = UIStoryboard(name: "Main", bundle: nil)
        let viewController = storyboard.instantiateViewController(withIdentifier : "SystemViewController") as! SystemViewController
       self.view.insertSubview(viewController.view!, belowSubview: self.tabBar)
        break
    default:
        break
    }
}

但是，这些都不起作用。 Segue 提供了一个新的 ViewController 和隐藏的标签栏。它将控件一起带到一个新的 viewcontroller。 我有两个疑问:

1. 当各个标签栏被标记时，如何在同一 View 中显示各个 View Controller ？
2. 如何使用显示有初始 View Controller 的标签栏加载 View Controller ？假设加载带有选项卡栏的 View Controller 时，还应显示要显示在第一个选项卡上的 View Controller 。

Answer 1

您正在尝试的函数 public func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) 是所选项目的 tabbar 委托(delegate)方法，您不能使用它来设置 tabbar Controller 。

在加载到内存之前，您应该为标签栏 Controller 提供 View Controller 。

试试看:

let viewController1 = storyboard.instantiateViewController(withIdentifier: "HardwareViewController") as? HardwareViewController
    let viewController2 = storyboard.instantiateViewController(withIdentifier: "SystemViewController") as! SystemViewController
    let viewController3 = storyboard.instantiateViewController(withIdentifier: "HardwareViewController") as! HardwareViewController
    let viewController4 = storyboard.instantiateViewController(withIdentifier : "SystemViewController") as! SystemViewController
    let viewController3 = storyboard.instantiateViewController(withIdentifier: "HardwareViewController") as! HardwareViewController

    var tabbarControllers = [viewController1, viewController2, viewController3, viewController4, viewController5]

   yourtabbarController.viewControllers = tabbarControllers
   // Now load your tabbar controller

完成关于 UITabbarController 的基本教程苹果公司。这是关于 viewControllers 的详细信息UITabbarController

的属性