iPad：没有“弹出按钮”的UISplitViewController？

Question

我有一个UISplitViewController（完美的工作），我想显示顶部的按钮，以纵向模式显示弹出菜单。

的AppDelegate代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 

    splitViewController = [[MySplitViewController alloc] init]; 

    MasterViewController *master = [[MasterViewController alloc] init]; 
    PicsTableViewController *detail = [[PicsTableViewController alloc] init]; 

    //create NavigationControllers 
    UINavigationController *masterNav = [[UINavigationController alloc] initWithRootViewController:master]; 
    UINavigationController *detailNav = [[UINavigationController alloc] initWithRootViewController:detail]; 

    [master release]; 

    splitViewController.viewControllers = [NSArray arrayWithObjects:masterNav, detailNav, nil]; 
    [masterNav release]; [detailNav release]; 
    splitViewController.delegate = detail; 
    [detail release]; 

    [self.window addSubview:splitViewController.view]; 
    [self.window makeKeyAndVisible]; 

    return YES; 
} 

PicsTableViewController（代表）代码：

//add button on top 
- (void)splitViewController:(UISplitViewController *)svc 
    willHideViewController:(UIViewController *)aViewController 
      withBarButtonItem:(UIBarButtonItem*)barButtonItem 
     forPopoverController:(UIPopoverController*)pc 
{ 
    barButtonItem.title = aViewController.title; 
    self.navigationItem.rightBarButtonItem = barButtonItem; 
} 

- (void)splitViewController:(UISplitViewController *)svc 
    willShowViewController:(UIViewController *)aViewController 
    invalidatingBarButtonItem:(UIBarButtonItem *)button 
{ 
    self.navigationItem.rightBarButtonItem = nil; 
} 

按钮一直没有出现，这有什么错我的代码？ 谢谢

Answer 1

检查aViewController实际上有一个title属性，如果没有任何字母那么按钮不会出现。

我有同样的问题，当我硬编码：

barButtonItem.title = [NSString stringWithFormat:@"hello"]; 

按钮露面和合作。

我认为引用导航没有标题，这就是为什么它不工作。