ios 6 横竖屏转换

程序的根控制器用了UINavigationController。下面是代码：

1.在appdelegate中添加代码：

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

{

    return UIInterfaceOrientationMaskAll;

}

2.给UINavigationController添加个category，在实现文件中添加如下代码：

-(BOOL)shouldAutorotate

{

    return [[self topViewController] shouldAutorotate];

}

-(NSUInteger)supportedInterfaceOrientations

{

    return [[self topViewController] supportedInterfaceOrientations];

}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation

{

    return [[self topViewController] preferredInterfaceOrientationForPresentation];

}

3.在需要横屏的地方添加（竖屏可以更换方向）：

-(NSUInteger)supportedInterfaceOrientations{

    return UIInterfaceOrientationMaskLandscapeRight;  // 可以修改为任何方向

}

-(BOOL)shouldAutorotate{

    return YES;

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {

    return interfaceOrientation == UIInterfaceOrientationLandscapeRight;

}

4.最重要的是：页面之间切换不能用导航控制器切换，必须使用：

[self presentViewController:navigationController animated:YES completion:Nil];