在iOS 6中，shouldAutorotateToInterfaceOrientation方法没有被调用。

事实证明，只有根视图处理这些调用。在我的情况下，这是一个普通的UINavigationController。我不得不将其更改为一个子类文件，在其中添加了这些方法。

在我的情况下，我只想让根视图竖屏显示，其他视图可以横竖屏切换。

Appdelegate.h

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    S2MBookAppRootViewController *masterViewController = [[[S2MBookAppRootViewController alloc] initWithNibName:pref.rootNibName bundle:nil] autorelease];
    self.navigationController = [[[S2MBookAppNavController alloc] initWithRootViewController:masterViewController] autorelease];

    self.window.rootViewController = self.navigationController;


    [self.window makeKeyAndVisible];
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque animated:YES];

    return YES;
}

同时，S2MBookAppNavController（UINavigationController的子类）

- (BOOL)shouldAutorotate {
    return YES;
}

- (NSUInteger)supportedInterfaceOrientations
{
    if([self.viewControllers count] == 1) return UIInterfaceOrientationMaskPortrait;
    return UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskLandscape;
}

更新： 当你想要强制改变方向（在导航控制器上推入一个新视图时）尝试以下方法。

将你的UINavigationController设为自己的代理：

@interface S2MBookAppNavController : UINavigationController <UINavigationControllerDelegate>

@end

在.m文件中

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.delegate = self;
    // Do any additional setup after loading the view.
}

- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
        if ([UIViewController respondsToSelector:@selector(attemptRotationToDeviceOrientation)]) {
            //present/dismiss viewcontroller in order to activate rotating.
            UIViewController *mVC = [[[UIViewController alloc] init] autorelease];
            [self presentModalViewController:mVC animated:NO];
            [self dismissModalViewControllerAnimated:NO];
        }
}

是的，问题只在于window.rootViewController方法调用返回方向掩码。 因此，在设置为window.rootViewController的viewController中必须实现supportedInterfaceOrientations方法。但在大多数情况下，该对象不是自定义类的对象，例如UINavigationController。一种可能的解决方案是子类化UINavigationController。但是Apple表示：“此类不适合子类化”，因此我宁愿使用另一个UIViewController来处理方向，并将UINavigationController添加为子视图。

MyRootViewController * myRoot = [MyRootViewController new];
self.window.rootViewController = myRoot;
[myRoot addChildViewController:navigationController];
[myRoot.view addSubview:navigationController.view];

在MyRootViewController中实现方法：

- (BOOL)shouldAutorotate {
 return YES;
}

- (NSUInteger)supportedInterfaceOrientations
{
    // return your mask here e.g.:
    return UIInterfaceOrientationMaskPortrait;
}

Apple已经在iOS6中弃用了shouldautorate方法，请改用这些方法。请参阅您的Xcode文档。

- (BOOL)shouldAutorotate NS_AVAILABLE_IOS(6_0);
- (NSUInteger)supportedInterfaceOrientations NS_AVAILABLE_IOS(6_0);
// Returns interface orientation masks.
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation NS_AVAILABLE_IOS(6_0);

我有一系列的视图控制器在一个UINavigationController中，其中一个必须是横屏模式。我通过子类化UINavigationController并添加以下代码来解决问题：

- (NSUInteger)supportedInterfaceOrientations{
   return [[self.viewControllers lastObject] supportedInterfaceOrientations];
}

- (NSUInteger)supportedInterfaceOrientations{
   if(UIDeviceOrientationIsPortrait([[UIDevice currentDevice] orientation]))       
      return UIInterfaceOrientationMaskPortrait;
   else
      return UIInterfaceOrientationMaskLandscape;
}

-(BOOL)shouldAutorotate
{
    UIDeviceOrientation orientation = [UIDevice currentDevice].orientation;

    if (orientation == UIDeviceOrientationUnknown) {
        return YES;
    }

    return [self shouldAutorotateToInterfaceOrientation:self.interfaceOrientation];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

至

- (void)viewWillLayoutSubviews

可以考虑直接替换这个部分，但我还没有在旧版 iOS 上进行测试。

如果您想限制支持的方向，应该在 UIApplicationDelegate 层面上进行设置。

-(NSUInteger)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window

-(NSUInteger)supportedInterfaceOrientations

即使方法被调用，也要返回值。

这对我有效：

- (BOOL)shouldAutorotate {
    return YES;
}

- (NSUInteger)supportedInterfaceOrientations {
    NSUInteger orientations = UIInterfaceOrientationMaskPortrait;
    if ([self isKindOfClass:[YourViewController class]]) { // Your view class
        orientations |= UIInterfaceOrientationMaskPortraitUpsideDown;
    }
    return orientations;
}

方向：

orientations |= UIInterfaceOrientationMaskLandscapeLeft;
orientations |= UIInterfaceOrientationMaskLandscapeRight;