Enforce device rotation by using a temporary window and view controller.

gistfile1.m

@interface FixedViewController : UIViewController
@property(nonatomic) NSUInteger supportedInterfaceOrientations;
@end

@implementation FixedViewController
@end

...

- (void)rotateToInterfaceOrientation:(UIInterfaceOrientation)orientation
{
	UIWindow *window = [[UIWindow alloc] initWithFrame: UIScreen.mainScreen.bounds];
	[window makeKeyAndVisible];
	
	FixedViewController *vc = [FixedViewController new];
	vc.supportedInterfaceOrientations = 1 << orientation;
	window.rootViewController = vc;
	
	window.hidden = YES;
}