IOS 永远保持横竖屏方法

1,PortraitViewController 不旋转，保持竖屏

//iOS 5
- (BOOL) shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
{
	return (toInterfaceOrientation == UIInterfaceOrientationPortrait);
}
//iOS 6
- (BOOL)shouldAutorotate
{
	return NO;
}
- (NSUInteger)supportedInterfaceOrientations
{
	return UIInterfaceOrientationMaskPortrait;
}
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
	return UIInterfaceOrientationPortrait;
}

2.LandscapeViewController 始终保持横屏

//iOS 5
- (BOOL) shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
{
	return (toInterfaceOrientation == self.preferredInterfaceOrientationForPresentation);
}
//iOS 6
- (BOOL) shouldAutorotate
{
	return YES;
}
- (NSUInteger)supportedInterfaceOrientations
{
	return UIInterfaceOrientationMaskLandscapeRight;
}
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
	return UIInterfaceOrientationLandscapeRight;
}