当我在 iOS 4.3 中调用 ViewDidAppear 时它不起作用？

Question

我有一个 UITabBarController，其中包括四个 UIViewController，当我想调用 viewDidAppear 时它不起作用。我不明白为什么只有 iOS 4.3 才会出现这种情况？

//
UINavigationController *nav3 = [[UINavigationController alloc] init];
SearchViewController *searchViewController = [[SearchViewController alloc] init];
searchViewController.context = context;

[nav3 pushViewController:searchViewController animated:NO];
[arrayViewController addObject:nav3];

[nav3 release]; [searchViewController release];

//
UINavigationController *nav4 = [[UINavigationController alloc] init];
FavorisViewController *favorisViewController = [[FavorisViewController alloc] init];
favorisViewController.context = context;

[nav4 pushViewController:favorisViewController animated:NO];
[arrayViewController addObject:nav4];

[nav4 release]; [favorisViewController release];

我最喜欢的 UIViewController：

     #pragma mark - View lifecycle

     - (void)viewDidLoad
      {
         [super viewDidLoad];

          NSError *error;
          NSFetchRequest *fetch = [[NSFetchRequest alloc] init];
          fetch.entity = [NSEntityDescription entityForName:@"Businesses" inManagedObjectContext:context];
          fetchObject = [context executeFetchRequest:fetch error:&error];

         [fetch release];

        }

      - (void)viewDidAppear:(BOOL)animated
       {
          NSLog(@"test");
       }

Answer 1

尝试使用 UINavigationController 方法 initWithRootViewController: 代替。例如，

FavorisViewController *favorisViewController = [[FavorisViewController alloc] init];
favorisViewController.context = context;
UINavigationController *nav4 = [[UINavigationController alloc] initWithRootViewController:favorisViewController];
[favorisViewController release];

还要注意，仅仅因为视图被推入堆栈，并不意味着它是可见的。在您选择具有该视图的选项卡之前，不应调用 viewDidAppear:。