objective-c - 执行 popToRootViewController 后如何将视图控制器推送到导航堆栈

Question

仅在将堆栈弹出到 rootviewcontroller 后，我才尝试将新的视图控制器推送到导航堆栈

//Select the tab I want to go to
self.tabBarController.selectedIndex = FEEDPAGE_INDEX;

//Retrieve the navcon in the feed page
UINavigationController *navcon = (UINavigationController*)[self.tabBarController.viewControllers objectAtIndex:FEEDTAB_INDEX];

//Pop to root view controller here
[navcon popToRootViewControllerAnimated:YES];

//Push a new root view controller onto stack
QuestionAnswerViewController *x = [[QuestionAnswerViewController alloc]init];
[navcon pushViewController:x animated:YES];

推送不起作用，即没有显示新页面。似乎 popToRootViewController 导致这种情况发生（不确定）。关于如何弹出然后推送新页面的任何建议？

Answer 1

QuestionAnswerViewController *x = [[QuestionAnswerViewController alloc]init];
UINavigationController *navcon = (UINavigationController*)[self.tabBarController.viewControllers objectAtIndex:FEEDTAB_INDEX];
NSArray *arr = [navcon viewControllers];
NSArray *newStack = [NSArray arrayWithObjects:[arr objectAtIndex:0], x, nil];
[navcon setViewControllers:newStack];