添加一个 UITabBarItem 到一个已经存在的 UITabBar（在故事板中制作）

Question

因此，我需要向在故事板中创建的现有 UITabBar 添加一个新的 UITabBarItem。

到目前为止，我认为我已经能够适当地访问 UITabBar，但无法创建 UITabBarItem 并将其添加到 UITabBar。

到目前为止，我得到的是：

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    var tabBarController = self.window!.rootViewController as UITabBarController
    var tabBar = tabBarController.tabBar as UITabBar

    var tabBarItem1 = tabBar.items![0] as UITabBarItem
    var tabBarItem2 = tabBar.items![1] as UITabBarItem
    var tabBarItem3 = tabBar.items![2] as UITabBarItem

    tabBarItem1.selectedImage = UIImage(named: "tab-frame-on")
    tabBarItem2.selectedImage = UIImage(named: "tab-quote-on")
    tabBarItem3.selectedImage = UIImage(named: "tab-hash-on")

    var instaTab: UITabBarItem = UITabBarItem(title: "", image: UIImage(named: "tab-instagram-off"), selectedImage: UIImage(named: "tab-instagram-on"))
    tabBar.items?.append(instaTab)

    return true

}

此函数是 AppDelegate 的一部分。正如您在第 14 行看到的那样，我正在创建 UITabBarItem，如下所示：var instaTab: UITabBarItem = UITabBarItem(title: "", image: UIImage(named: "tab-instagram-off"), selectedImage: UIImage(named: "tab-instagram-on"))，然后尝试通过附加它来将其添加到预先存在的选项卡栏项目中。这让我在 AppDelegate class 实例化时出现 SIGABRT 错误。

我做错了什么？

Answer 1

如果您查看 Xcode 控制台，它应该会告诉您哪里做错了。

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Directly modifying a tab bar managed by a tab bar controller is not allowed.'

tabBar.items由UITabBarController控制。您必须改为修改 UITabBarController 的 viewControllers 属性。

例如：

tabBarItem3.selectedImage = UIImage(named: "tab-hash-on")


let instaViewController = UIViewController()
instaViewController.tabBarItem = UITabBarItem(title: "", image: UIImage(named: "tab-instagram-off"), selectedImage: UIImage(named: "tab-instagram-on"))

var viewControllers = tabBarController.viewControllers!
viewControllers.append(instaViewController)
tabBarController.viewControllers = viewControllers


return true

添加一个 UITabBarItem 到一个已经存在的 UITabBar（在故事板中制作）

Add a UITabBarItem to an already existing UITabBar (made in storyboard)

xcode

storyboard

uitabbarcontroller

swift