推送跳转到N级界面 返回那些事

- (void)backButtonAction {

    UINavigationController *navigationController = self.navigationController;
    NSMutableArray<__kindof UIViewController *> *tempViewControllers = [NSMutableArray arrayWithArray:navigationController.viewControllers];

    //TODO: 判断栈中是否含有B控制器   如果没有就添加B控制器
    BOOL canAddBVC = YES;
    for(UIViewController*controller in self.navigationController.viewControllers) {
        if([controller isKindOfClass:[BViewController class]]) {
            canAddBVC = NO;
        }
    }
    
    //TODO: 添加B 控制器到第二级
    if (canAddBVC) {
        BViewController *tempBVC = [BViewController new];
        [tempViewControllers insertObject:tempBVC atIndex:1];
        navigationController.viewControllers = tempViewControllers;
    }
    
    
    //TODO: 判断自身控制器在栈中的个数    个数多于一个则移除先入栈的自身
    int selfCountInViewControllers = 0;
    for(UIViewController*controller in tempViewControllers) {
        if([controller isKindOfClass:[CViewController class]]) {
            selfCountInViewControllers++;
        }
    }
    
    //TODO: 移除先入栈的自身
    if (selfCountInViewControllers > 1) {
        [tempViewControllers removeObjectAtIndex:tempViewControllers.count - 2];
        navigationController.viewControllers = tempViewControllers;
    }

    [navigationController popToViewController:navigationController.viewControllers[1] animated:YES];
}