ios - 以编程方式将 UIBarButtonItem 添加到 UITabBarController 内的所有导航 View Controller

Question

结构如下:

• 查看
• 标签栏 Controller
  • 导航 Controller
    • View Controller
  • 导航 Controller
    • View Controller
  • 导航 Controller
    • View Controller
  • 导航 Controller
    • View Controller
  • 导航 Controller
    • View Controller
  • 导航 Controller
    • View Controller

以上 Controller 已在界面生成器中初始化。

我想做的是向每个导航 Controller 添加一个正确的 UIBarButtonItem 但没有成功。

这是我尝试过的:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor clearColor];
    self.view.opaque = NO;
    self.tabBarController.view.frame = self.view.bounds;

    NSArray *currentViewControllers = self.tabBarController.viewControllers;
    NSMutableArray *updatedViewControllers = [NSMutableArray array];

    for (int i=0; i<currentViewControllers.count; i++) {
        UINavigationController *tempNav = [[UINavigationController alloc]init];
        tempNav = [currentViewControllers objectAtIndex:i];
        UIBarButtonItem *dismissButton = [[UIBarButtonItem alloc] 
                                          initWithTitle:@"Done"                                            
                                          style:UIBarButtonItemStyleBordered 
                                          target:self 
                                          action:@selector(dismissLibraryBrowser)];
        tempNav.navigationItem.rightBarButtonItem = dismissButton;
        [updatedViewControllers addObject:tempNav];
        [dismissButton release];
        [tempNav release];

        NSLog(@"Added controller number %d",i);
    }

    self.tabBarController.viewControllers = [NSArray arrayWithArray:updatedViewControllers];

    [self.view addSubview:tabBarController.view];
}

代码执行没有任何错误，但按钮没有出现。我确定我在这里误解了一些东西。希望得到一些指导。

Answer 1

您通过重新创建 viewController 和临时数组使事情稍微复杂化。你只需要操作从 Nib 加载的对象

[self.tabBarController.viewControllers enumerateObjectsUsingBlock:^(UINavigationController *navigationController, NSUInteger idx, BOOL *stop) {

    UIViewController *rootViewController = [navigationController.viewControllers objectAtIndex:0];

    UIBarButtonItem *rightBarButtonItem  = 
      [[UIBarButtonItem alloc] initWithTitle:@"Done"                                            
                                       style:UIBarButtonItemStyleBordered 
                                      target:self 
                                      action:@selector(dismissLibraryBrowser)];

    rootViewController.navigationItem.rightBarButtonItem = rightBarButtonItem;

 }];

---

关于您的应用程序的结构 - UITabBarController 的文档说

When deploying a tab bar interface, you must install this view as the root of your window. Unlike other view controllers, a tab bar interface should never be installed as a child of another view controller.

所以我建议看看重构一些东西，如果你只是偶尔需要它，为什么不考虑以模态方式呈现它呢？