iOS Xamarin 将 tabBar 推到导航 Controller 上

Question

我有一个登录屏幕，用户登录后，我希望选项卡位于底部，并在顶部有一个导航栏。我可以选择其中之一，但不能同时获得两者。可能吗？

    partial void LoginButton_TouchUpInside(UIButton sender)
    {
            // push tab controller
            tabController = new MyTabBarController();
            navController = new UINavigationController();
            navController.PushViewController(tabController, true);
    }

应用程序委托(delegate):

public override bool FinishedLaunching(UIApplication application, 
NSDictionary 
launchOptions)
    {
        // Override point for customization after application launch.
        // If not required for your application you can safely delete 
       this method

        //set root view controller
        Window = new UIWindow(UIScreen.MainScreen.Bounds);

        //Create navigation controller and tab controller
        UINavigationController navctrl = new 
   UINavigationController(new 
        StartViewController());
        MyTabBarController tabController = new MyTabBarController();

        Window.RootViewController = navctrl;

        Window.MakeKeyAndVisible();

        return true;
    }

Answer 1

您需要先将 UINavigationController 设置为 RootViewController ，然后将 TabBarController 添加到 UINavigationController ，然后就可以工作了。如下:

Window = new UIWindow(UIScreen.MainScreen.Bounds);

// Set up the first View Controller
var vc1 = new UIViewController();
vc1.View.BackgroundColor = UIColor.Orange;
vc1.TabBarItem.Title = "Orange";

// Set up the second View Controller
var vc2 = new UIViewController();
vc2.View.BackgroundColor = UIColor.Purple;
vc2.TabBarItem.Title = "Purple";

// Set up the Tab Bar Controller to have two tabs
var tabBarController = new UITabBarController();
tabBarController.ViewControllers = new UIViewController[] {vc1,vc2};

var registerController = new UINavigationController(tabBarController);

Window.RootViewController = registerController;
Window.MakeKeyAndVisible();

顺便说一句，从 iOS 13 开始，您最好在 SceneDelegate.cs 的方法(WillConnect)中编写代码来设置 RootViewController 。

public void WillConnect (UIScene scene, UISceneSession session, UISceneConnectionOptions connectionOptions)
{
    // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
    // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
    // This delegate does not imply the connecting scene or session are new (see UIApplicationDelegate `GetConfiguration` instead).

    UIWindowScene windowScene = new UIWindowScene(session, connectionOptions);

    // Set up the first View Controller
    var vc1 = new UIViewController();
    vc1.View.BackgroundColor = UIColor.Orange;
    vc1.TabBarItem.Title = "Orange";

    // Set up the second View Controller
    var vc2 = new UIViewController();
    vc2.View.BackgroundColor = UIColor.Purple;
    vc2.TabBarItem.Title = "Purple";

    // Set up the Tab Bar Controller to have two tabs
    var tabBarController = new UITabBarController();
    tabBarController.ViewControllers = new UIViewController[] {vc1,vc2};

    var registerController = new UINavigationController(tabBarController);
    this.Window = new UIWindow(windowScene);
    this.Window.RootViewController = registerController;
    this.Window.MakeKeyAndVisible();
}