开发过程中，总是遇到一个或多个ViewController需要支持屏幕旋转，而其他不需要的情况，故需要特殊处理需要旋转的ViewController，而不影响其他。
iOS的屏幕旋转是由根视图控制的，只要重写根视图的-(BOOL)shouldAutorotate和-(UIInterfaceOrientationMask)supportedInterfaceOrientations方法即可，当前举例以UITabBarController+UINavigationController：
选择Device Orientation
Device Orientation
新建类别UITabBarController+Orientation
@implementation UITabBarController (Orientation)
- (BOOL)shouldAutorotate
{
return [self.selectedViewController shouldAutorotate];
}
- (NSUInteger)supportedInterfaceOrientations
{
return [self.selectedViewController supportedInterfaceOrientations];
}
@end
UINavigationController+Orientation
@implementation UINavigationController (Orientation)
- (BOOL)shouldAutorotate
{
return [self.topViewController shouldAutorotate];
}
- (NSUInteger)supportedInterfaceOrientations
{
return [self.topViewController supportedInterfaceOrientations];
}
@end
UIViewController+Orientation
@implementation UIViewController (Orientation)
- (BOOL)shouldAutorotate
{
return YES;
}
- (NSUInteger)supportedInterfaceOrientations
{
return UIInterfaceOrientationMaskPortrait;
}
@end
这样处理之后，UIViewController默认仅支持垂直方向，若有支持多方向需求，再单独重写Controller的-(BOOL)shouldAutorotate和-(UIInterfaceOrientationMask)supportedInterfaceOrientations方法即可。
