iOS5 SplitViewController 在应用程序启动时在横向视图中使 BarButton 保持可见

Question

我有一个 UISplitViewController，其中一个 UIViewController 作为主控制器，一个 UINavigationController 作为我的详细信息控制器（其中包含一个实际的DetailsController，因为它是 rootController）。

在 iOS5 中，在应用程序启动时（将设备保持在横向视图中），我将 splitViewController 的视图添加到我的窗口中，但随后我在 splitViewController 之上呈现一个登录控制器，如下所示：

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

    KRMasterViewController *masterViewController = [[[KRMasterViewController alloc] initWithNibName:@"KRMasterViewController" bundle:nil] autorelease];
    UINavigationController *masterNavigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease];

    KRDetailViewController *detailViewController = [[[KRDetailViewController alloc] initWithNibName:@"KRDetailViewController" bundle:nil] autorelease];
    UINavigationController *detailNavigationController = [[[UINavigationController alloc] initWithRootViewController:detailViewController] autorelease];

    self.splitViewController = [[[UISplitViewController alloc] init] autorelease];
    self.splitViewController.delegate = detailViewController;
    self.splitViewController.viewControllers = [NSArray arrayWithObjects:masterNavigationController, detailNavigationController, nil];
    [self.window addSubview:self.splitViewController.view];

    LoginController *controller=[[LoginController alloc]
                                        initWithNibName:@"LoginController" bundle:nil];
    [self.splitViewController presentModalViewController:controller animated:false];

    [self.window makeKeyAndVisible];
    return YES;
}

如您所见，detailsController 是我的 splitViewController 的委托。问题是在iOS4中，在显示loginController之前，调用委托方法：

- (void)splitViewController:(UISplitViewController *)splitController willHideViewController:(UIViewController *)viewController withBarButtonItem:(UIBarButtonItem *)barButtonItem 
       forPopoverController:(UIPopoverController *)popoverController

然后当我关闭loginController时

- (void)splitViewController:(UISplitViewController *)splitController willShowViewController:(UIViewController *)viewController invalidatingBarButtonItem:(UIBarButtonItem *)barButtonItem

调用委托方法：。我想 iOS 很晚才意识到我处于横向状态，但在我到达细节控制器之前就发现了，所以一切都很酷。在 iOS 5 中，当我到达 splitViewController 时，第二个方法不会被调用。这意味着我留下了在横向视图中可见的 barButtonItem 。有趣的是，如果我旋转到纵向然后再回到横向，从那时起这些方法就会被正确调用。以前有人经历过这种情况吗？有什么解决办法吗？

Answer 1

我也遇到过类似的问题。应用程序启动后，我会显示登录 modalVC。但是当我关闭它时，detailViewController 中的 BarButtonItem 仍然可见。

只要使用

[self performSelector:@selector(presentLogin) withObject:nil afterDelay:0.1]

它就会神奇地开始工作。

Answer 2

我最终将根控制器从导航控制器（登录时）切换为主菜单的 splitview 控制器：

-(void)goToLogin{
   self.rootSplitController=nil;

   UINavigationController* navController=[[UINavigationController alloc]init];
   navController.navigationBarHidden = true;
   self.rootNavController=navController;
   [navController release];

   LoginController *loginController=[[LoginController alloc]init];
   [self.rootNavController pushViewController:loginController animated:false];
   [loginController release];

   [self.window addSubview:self.rootNavController.view];
}

-(void)goToMain{
   self.rootNavController=nil;

   MasterController *masterViewController = [[[MasterController alloc] 
      initWithNibName:@"MasterController" bundle:nil] autorelease];
   UINavigationController *masterNavigationController = [[[UINavigationController alloc] 
      initWithRootViewController:masterViewController] autorelease];
   masterNavigationController.navigationBarHidden=true;

   DetailsController *detailViewController = [[[DetailsController alloc] 
      initWithNibName:@"DetailsController" bundle:nil] autorelease];
   UINavigationController *detailNavigationController = [[[UINavigationController alloc] 
      initWithRootViewController:detailViewController] autorelease];
   detailNavigationController.navigationBarHidden=true;

   self.rootSplitController = [[[UISplitViewController alloc] init] autorelease];
   self.rootSplitController.delegate = detailViewController;
   self.rootSplitController.viewControllers = [NSArray arrayWithObjects:
    masterNavigationController, detailNavigationController, nil];

   [self.window addSubview:self.rootSplitController.view];
}