如何以编程方式创建标签栏控制器后添加导航界面（Swift）

Question

在AppDelegate/didFinishLaunchingWithOptions 上创建TabBarController 后，如何以编程方式在Swift 上添加导航 界面。这是我当前的代码：

self.window = UIWindow(frame: UIScreen.mainScreen().bounds)


    let tabBarController = UITabBarController()
    let purchaseViewController = PurchaseViewController(nibName: "PurchaseViewController", bundle: nil)
    let financeViewController = FinanceViewController(nibName: "FinanceViewController", bundle: nil)



    tabBarController.viewControllers = [purchaseViewController, financeViewController]

    self.window!.rootViewController = tabBarController
    self.window!.makeKeyAndVisible()

我正在查看文档。它有以下准则

- (void)applicationDidFinishLaunching:(UIApplication *)application {
self.tabBarController = [[UITabBarController alloc] init];

MyViewController1* vc1 = [[MyViewController1 alloc] init];
MyViewController2* vc2 = [[MyViewController2 alloc] init];
MyViewController3* vc3 = [[MyViewController3 alloc] init];
MyNavRootViewController* vc4 = [[MyNavRootViewController alloc] init];
UINavigationController* navController = [[UINavigationController alloc]
                        initWithRootViewController:vc4];

NSArray* controllers = [NSArray arrayWithObjects:vc1, vc2, vc3, navController, nil];
tabBarController.viewControllers = controllers;

window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
window.rootViewController = tabBarController;
[window makeKeyAndVisible];
}

问题，我不知道如何在 Swift 上正确执行此操作。我希望在AppDelegate 中以单独的方法设置和修改NavigationBar。有什么想法吗？

Answer 1

要创建导航控制器，请使用：

var navigationController = UINavigationController(rootViewController: viewController));

然后直接放入数组中：

tabBarController.viewControllers = [purchaseViewController, financeViewController, navigationController]

但是，您只能在视图控制器加载后才能将 UIControls 添加到导航栏。在applicationDidFinishLaunching: 上是不可能的，因为navigationBar 是零。正确的方法是在viewDidLoad()中给navigationBar添加控件