ObjC 如何在选择 TabBarItem 时弹出回 RootViewController

Question

我得到了以下流程

在主页选项卡 Select 晚上叫 [self.parentViewController.tabBarController setSelectedIndex:2]; 去 Class 选项卡

在 Class 选项卡 select 任何 Class

进入下一个VC

Select又是回家又是傍晚

停留在之前VC没有回到RootView

应该在这里

从 Home Tab 我执行 [self.parentViewController.tabBarController setSelectedIndex:2]; 到 Class Tab。然后从嵌入在 NavigationController 中的 Class 选项卡，然后我将使用 seague 转到下一个 VC 及以后。

但是当我再次 select Home Tab 时，我希望 Class Tab 回到 RootViewController

我试过以下方法，但没有用。每次下一个 VC 消失时，它都会一直弹出到 RootViewController。

   -(void) viewWillDisappear:(BOOL)animated {

       [self.navigationController popViewControllerAnimated:YES];

       [super viewWillDisappear:animated];
   }

我有以下代码 MyTabBarController，它是一位友善的堆栈溢出大师给我的，但不确定每次新的 TabBarController 是 select编辑。请帮忙。

 - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
    NSLog(@"didSelectViewController... ");

//==== Tried this but not triggering =====    
//[(UINavigationController *)viewController popToRootViewControllerAnimated:NO];
//if ([viewController isKindOfClass:[UINavigationController class]]) {
    //[self.navigationController popViewControllerAnimated:YES];
//}
//==========================================

    NSLog(@"controller class: %@", NSStringFromClass([viewController class]));
    NSLog(@"controller title: %@", viewController.title);

    if ([viewController isKindOfClass:[UINavigationController class]]) {

        // we're expecting a nav controller so cast it to a nav here
        UINavigationController *navController = (UINavigationController *)viewController;

        // now grab the first view controller from that nav controller
        UIViewController *firstViewControllerInNav = navController.viewControllers.firstObject;

        // check to make sure it's what we're expecting (ParentViewController)

       if ([firstViewControllerInNav isKindOfClass:[ParentViewController class]]) {
            // cast it to our parent view controller class
            [(UINavigationController *)viewController popToRootViewControllerAnimated:NO];
            ParentViewController *viewControllerToCallMethodOnAfterSelection = (ParentViewController *)firstViewControllerInNav;
            [viewControllerToCallMethodOnAfterSelection doStuffWhenTabBarControllerSelects];
        }else{
        //=== The following code will make viewWillAppear load on each tab bar item
        //=== Without it, tapping on new tab bar item will not load viewWillAppear
            [(UINavigationController *)viewController popToRootViewControllerAnimated:NO];
        }
    }


}

添加了以下代码，它会触发但不会将 selectedIndex = 2 带回 Root

-(BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
    NSUInteger shouldSelectIndex = [tabBarController.viewControllers indexOfObject:viewController];
    //Check if current index is Class tab and new index is Home
    if (tabBarController.selectedIndex == 2 && shouldSelectIndex == 0) {
        [self.navigationController popViewControllerAnimated:YES];
        //[(UINavigationController *)viewController popToRootViewControllerAnimated:NO];
        //[tabBarController.viewControllers objectAtIndex:tabBarController.selectedIndex];
    }
    return YES;
}

已添加故事板

添加文件结构

Answer 1

如果我理解正确，那么如果当前选项卡是 Class 并且选择了 Home 选项卡，您想返回到根视图。也许这会比使用 didSelectViewController:

更好

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
    NSUInteger shouldSelectIndex = [tabBarController.viewControllers indexOfObject:viewController];
    //Check if current index is Class tab and new index is Home
    if (tabBarController.selectedIndex == 2 && shouldSelectIndex == 0) {
       //Pop to root code with `[tabBarController.viewControllers objectAtIndex:tabBarController.selectedIndex]` (Class tab's navigation controller)
    }
    return YES;
}

Answer 2

使用下面的swift代码清除导航栏控制器数组

guard let child = self.childNavController else {return}

child.viewControllers = []

您可以在 objective C 中使用相同的选项卡栏选择方法

Answer 3

在您的 tabbarController 中创建一个方法，并在您希望 class 选项卡访问其根视图控制器时调用此方法

-(void)popToClassRootViewController{
    // Considering the fact that class view contorller will always be on 3 no and will be of UINavigationController
    UINavigationController *classNavController = (UINavigationController *)[self.viewControllers objectAtIndex:2];
    // You can get the navigation controller reference by any way you prefer
    [classNavController popToRootViewControllerAnimated:false];
}

在你的情况下，我认为你想要在单击其他选项卡时重置视图控制器，这样你就可以使用 tabbar 委托方法来检查是否单击了其他选项卡栏项目并调用该方法

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
    NSUInteger index = [tabBarController.viewControllers indexOfObject:viewController];
    if (index != 2) {
       //Note: Call this method according to your need in this case it will be called whenever user will select tab other then Class
       [self popToClassRootViewController];
    }
    return true;
}

ObjC 如何在选择 TabBarItem 时弹出回 RootViewController

ObjC how to pop back to RootViewController when TabBarItem is selected

objective-c

uitabbarcontroller

uinavigationcontroller

ios