Question

我不能为我的生活在我的每个标签栏项目视图中获得导航控制器（和栏）。这是我的appdelegate，我错过了什么？ FrontPage和Opinion也是tableviewcontrollers，只是忘了他们名字中的表格。

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:        (NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.

  FrontPageViewController *frontPageVC = [[FrontPageViewController alloc] initWithNibName:nil bundle:nil];
  frontPageVC.title = @"Front Page";
  frontPageVC.tabBarItem.image = [UIImage imageNamed:@"second"];
  UINavigationController *frontPageNavController = [[UINavigationController alloc] initWithRootViewController:frontPageVC];

  CampusTableViewController *campusVC = [[CampusTableViewController alloc] initWithNibName:nil bundle:nil];
  campusVC.title = @"Campus";
  campusVC.tabBarItem.image = [UIImage imageNamed:@"second"];
  UINavigationController *campusNavController = [[UINavigationController alloc] initWithRootViewController:campusVC];

  OpinionViewController *opinionVC = [[OpinionViewController alloc] initWithNibName:nil bundle:nil];
  opinionVC.title = @"Opinion";
  opinionVC.tabBarItem.image = [UIImage imageNamed:@"second"];
  UINavigationController *opinionNavController = [[UINavigationController alloc] initWithRootViewController:opinionVC];

  SportsTableViewController *sportsVC = [[SportsTableViewController alloc] initWithNibName:nil bundle:nil];
  sportsVC.title = @"Sports";
  sportsVC.tabBarItem.image = [UIImage imageNamed:@"second"];
  UINavigationController *sportsNavController = [[UINavigationController alloc] initWithRootViewController:sportsVC];

  PDFViewController *pdfVC = [[PDFViewController alloc] initWithNibName:nil bundle:nil];

  NSArray *controllers = [NSArray arrayWithObjects:frontPageVC, campusVC, opinionVC, sportsVC, pdfVC, nil];

  self.tabBarController = [[UITabBarController alloc] init];
  self.tabBarController.viewControllers = controllers;

  self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    return YES;

  [[self.tabBarController.viewControllers objectAtIndex:0] setRootViewController:frontPageNavController];

}

谢谢你！

编辑：显然我需要输入更多内容来解释我的问题，因为如果没有一定数量的话，SO会不会让我发帖？

Answer 1

更改此行

NSArray *controllers = [NSArray arrayWithObjects:frontPageVC, campusVC, opinionVC, sportsVC, pdfVC, nil];

到那个

UINavigationController *pdfNavController = [[UINavigationController alloc] initWithRootViewController:pdfVC];
NSArray *controllers = [NSArray arrayWithObjects:frontPageNavController, campusNavController, opinionNavController, sportsNavController, pdfNavController, nil];

Answer 2

您的controllers应包含导航控制器，而不是单个控制器。

NSArray *controllers = [NSArray arrayWithObjects:frontPageNavController, campusNavController, opinionNavController, sportsNavController, pdfNavController, nil];

self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController.viewControllers = controllers;

self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
return YES;

// you can remove the last line: [[self.tabBarController.viewControllers objectAtIndex:0] setRootViewController:frontPageNavController];

Apple在文档中说（不记得是否在人机界面指南中，在视图控制器编程，标签栏控制器编程或导航控制器编程中），如果你想拥有导航控制器和标签栏控制器，你必须将导航控制器放在标签栏控制器内。

Answer 3

为什么在return语句之后给出这个方法？

[[self.tabBarController.viewControllers objectAtIndex：0] setRootViewController：frontPageNavController];

尝试在return语句之前给出这个或删除此语句。因为你返回下一行不会执行。还要清楚地告诉我们您的问题。你想做什么。

在appDelegate.m中设置导航控制器和tabBarController

3 个答案: