swift - 从 Tabbar 更改 ViewController

Question

我有一个带有 3 个选项卡的 UITabBarController 和一个 SettingsVC，您可以在其中选择 MainVC 的外观(有 2 个不同的 ViewControllers 基于用户的偏好应该显示为 MainVC)。

我制作了应用程序并且它可以工作，但它确实有问题，因为我只是将 ViewControllers 推到彼此之上，在某些特定情况下，您会在切换 tabs< 时看到错误.

Main.storyboard

这是我的代码的一部分(在尝试了很多东西之后)，它根据 UserDefaults

更改了 VC

CheckSettingsStatus.swift

//
// Check for Double Column Settings and navigate to Double Column VC
//
func checkMainVCViewStatusAndNavigateAcordingly(){
    if UserDefaults.standard.integer(forKey: KEY_MAIN_VC_VIEW) == 1{
        //let appDel = UIApplication.shared.delegate as! AppDelegate
        //appDel.goToDoubleMainVC()

        let mainVC = storyboard?.instantiateViewController(withIdentifier: "DoubleColumnMainVC") as! DoubleColumnMainVC
        self.navigationController?.viewControllers[0] = mainVC
        //navigationController?.pushViewController(mainVC, animated: false)

        var navigationArray = self.navigationController?.viewControllers
        print("Number of VCs = \(String(describing: navigationArray?.count))")
        if navigationArray?.count == nil{
            self.navigationController?.pushViewController(mainVC, animated: false)
        }else{
            self.navigationController?.popToRootViewController(animated: false)
        }
        //            self.navigationController?.viewControllers = navigationArray!
    }
}


//
// same as function above but goes to MainVC
//
func checkDoubleColumnMainVCViewStatusAndNavigateAcordingly(){
    if UserDefaults.standard.integer(forKey: KEY_MAIN_VC_VIEW) == 0{
        //            let appDel = UIApplication.shared.delegate as! AppDelegate
        //            appDel.goToMainVC()
        let mainVC = storyboard?.instantiateViewController(withIdentifier: "MainVC") as! MainVC
        self.navigationController?.viewControllers[0] = mainVC

        var navigationArray = self.navigationController?.viewControllers
        print("Number of VCs = \(String(describing: navigationArray?.count))")
        if navigationArray?.count == nil{
            navigationController?.pushViewController(mainVC, animated: false)
        }else{
            self.navigationController?.popToRootViewController(animated: false)
        }
        //            self.navigationController?.viewControllers = navigationArray!
    }
}

在这两个 Controller 的 ViewWillAppear 中，我调用这些函数进行相应的切换。

知道我做错了什么吗？我可以从 UITabBarController 而不是 NavigationController 推送 Controller 吗？像这样的东西:

tabBarController.pushViewController(mainVC, animated: false)

代替:

navigationController.pushViewController(mainVC, animated: false)

提前致谢

更新:

在我最好的情况下，当一切正常时，在第一次启动应用程序时(到第二个 mainVC)，NavBar 中的 Buttons 没有'工作。

编辑:

我刚刚意识到我在 SecondMainVC 上方看到的 NavigationBar 是来自 MainVC 的 NavigationBar ，这就是按钮不起作用的原因。这怎么可能？

Answer 1

我在尝试在 Storyboard中开发标签栏 Controller 时遇到了同样的问题，因此我发现最好的方法是通过代码实现它。所以你可以让你的代码看起来像这样:

1) 创建一个UITabController的子类，并让它符合UITabBarControllerDelegate

  class TabBarVC: UITabBarController , UITabBarControllerDelegate {

2)然后在你的类中编写这个方法来初始化你项目中的选项卡:

  private func settingUpTabBarAndInitializingViewControllers(){

    //self delagting
    self.delegate = self 

    //home tab
    let homeStoryboard = UIStoryboard(name: Constants.StoryBoards.homeStoryboard, bundle: nil)
    let homeVC = homeStoryboard.instantiateViewController(withIdentifier: Constants.ControllersIDs.homeScreen) as! HomeVC

    // shop tab
    let shopStoybaord = UIStoryboard(name: Constants.StoryBoards.shopStoryboard, bundle: nil)
    let shopVC = shopStoybaord.instantiateViewController(withIdentifier: Constants.ControllersIDs.shopScreen) as! ShopVC

    //offers tab
    let offersStoryboard = UIStoryboard(name: Constants.StoryBoards.offersStoryboard, bundle: nil)
    let offersVC = offersStoryboard.instantiateViewController(withIdentifier: Constants.ControllersIDs.offersScreen) as! OffersVC

    //more tab
    let moreStoryboard = UIStoryboard(name: Constants.StoryBoards.MoreScreenStoryboard, bundle: nil)
    let moreVC = moreStoryboard.instantiateViewController(withIdentifier: Constants.ControllersIDs.moreVCScreen) as! MoreOptionsTVC


    //setting VCs
    self.viewControllers = [homeVC , shopVC , offersVC , moreVC]


    //setting buttons

    //buttons images
    let homeImage = UIImage(named: "TabHome")
    let shopImage = UIImage(named : "TabShop")
    let offerImage = UIImage(named: "TabOffers")
    let moreImage = UIImage(named: "TabMenu")


    // buttons shakhsiyan
    let homeButton = UITabBarItem(title: homeText, image: homeImage, selectedImage: homeTappedImage)
    let shopButton = UITabBarItem(title: shopText, image: shopImage, selectedImage: shopTappedImage)
    let offersButton = UITabBarItem(title: offersText, image: offerImage, selectedImage: offersTappedImage)     
    let moreButton = UITabBarItem(title: moreText, image: moreImage, selectedImage: moreTappedImage)


    homeVC.tabBarItem = homeButton
    shopVC.tabBarItem = shopButton
    offersVC.tabBarItem = offersButton
    moreVC.tabBarItem = moreButton

}

附言您可以根据需要添加尽可能多的选项卡，并且在其中滚动时您不会遇到任何错误，

确保在标签栏 Controller 之前只有一个导航 Controller 。