ios - UINavigationController 和 TabBarController 以编程方式(无 Storyboard)

Question

目前，我的 AppDelegate 文件包含将 CustomTabBarController 设置为 rootViewController 的代码:

window = UIWindow(frame: UIScreen.main.bounds)
window?.makeKeyAndVisible()
window?.rootViewController = CustomTabBarController()

我希望我的应用始终在底部具有 CustomTabBarController，但我希望每个选项卡都有一个导航 Controller 。这是我用来设置 tabBarController 的代码:

class CustomTabBarController: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
let vc1 = FirstViewController()
let vc2 = SecondViewController()
let vc3 = ThirdViewController()
viewControllers = [vc1, vc2, vc3]
}

这是我用来设置 FirstViewController 的代码:

class ProfileViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 2
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: VCCellId, for: indexPath) as! firstVCCell

    return cell
}
}

Answer 1

当组合 UITabBarController 和 UINavigationController 时，设置它的正确方法是使 UITabBarController 成为 rootViewController。 UITabBarController 的每个选项卡都有自己的 UINavigationController。因此，如果您有 4 个选项卡，您将创建 4 个 UINavigationControllers。

参见:Adding a Navigation Controller to a Tab Bar Interface

---

更新

根据您在更新后的问题中添加的代码，为您的每个 vc1、vc2 和 创建一个 UINavigationController >vc3.

class CustomTabBarController: UITabBarController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let vc1 = UINavigationController(rootViewController: FirstViewController())
        let vc2 = UINavigationController(rootViewController: SecondViewController())
        let vc3 = UINavigationController(rootViewController: ThirdViewController())

        viewControllers = [vc1, vc2, vc3]
    }

}

在您的每个 ViewController 中，将 title 设置为您希望在选择该选项卡时在导航栏中显示的标题:

class FirstViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .red
        title = "First"
        self.navigationController?.navigationBar.titleTextAttributes =
            [NSFontAttributeName: UIFont(name: "Chalkduster", size: 27)!,
             NSForegroundColorAttributeName: UIColor.black]
    }
}