iOS 8横向纵向模式下的自定义键盘

-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation 
duration:(NSTimeInterval)duration
{
    NSUserDefaults *def = [NSUserDefaults standardUserDefaults];
    if ((toInterfaceOrientation==UIInterfaceOrientationPorTrait) || (toInterfaceOrientation==UIInterfaceOrientationPorTrait))
    {
        [def setObject:@"No" forKey:@"LandScape"];
        [def synchronize];
        islandscapemode = NO;
        NSLayoutConsTraint *_heightConsTraint =
        [NSLayoutConsTraint consTraintWithItem: self.view
                                     attribute: NSLayoutAttributeHeight
                                     relatedBy: NSLayoutRelationEqual
                                        toItem: nil
                                     attribute: NSLayoutAttributeNotAnAttribute
                                    multiplier: 0.0
                                      constant: 266];

        [self.view addConsTraint:_heightconstraint];
           }
    else
    {
        [def setObject:@"Yes" forKey:@"LandScape"];
        [def synchronize];

        NSLayoutConsTraint *_heightConsTraint =
        [NSLayoutConsTraint consTraintWithItem: self.view
                                     attribute: NSLayoutAttributeHeight
                                     relatedBy: NSLayoutRelationEqual
                                        toItem: nil
                                     attribute: NSLayoutAttributeNotAnAttribute
                                    multiplier: 0.0
                                      constant: 266];

        [self.view addConsTraint:_heightconstraint];

        self.view.BACkgroundColor=[UIColor greenColor];

        islandscapemode = YES;

    }
    //  [self determineKeyboardNib:toInterfaceOrientation];
}

但它不起作用.我该怎么办？