Rotate UIViewController to counteract changes in UIInterfaceOrientation

I've been searching a lot on this,开发者_开发知识库 and can't find anything to help me.

I have a UIViewController contained within another UIViewController. When the parent UIViewController rotates, say from Portrait to LandscapeLeft, I want to make it look as though the child didn't rotate. That is to say. I want the child to have the same orientation to the sky regardless of the parent's orientation. If it has a UIButton that's upright in Portrait, I want the right-side of the button to be "up" in UIInterfaceOrientationLandscapeLeft.

Is this possible? Currently, I'm doing really gross stuff like this:

-(void) rotate:(UIInterfaceOrientation)fromOrientation: toOr:(UIInterfaceOrientation)toOrientation
{
    if(((fromOrientation == UIInterfaceOrientationPortrait) && (toOrientation == UIInterfaceOrientationLandscapeRight))
       || ((fromOrientation == UIInterfaceOrientationPortraitUpsideDown) && (toOrientation == UIInterfaceOrientationLandscapeLeft)))
    {

    }
    if(((fromOrientation == UIInterfaceOrientationLandscapeRight) && (toOrientation == UIInterfaceOrientationPortraitUpsideDown))
       || ((fromOrientation == UIInterfaceOrientationLandscapeLeft) && (toOrientation == UIInterfaceOrientationPortrait)))
    {

    }
    if(((fromOrientation == UIInterfaceOrientationPortrait) && (toOrientation == UIInterfaceOrientationLandscapeLeft))
       || ((fromOrientation == UIInterfaceOrientationPortraitUpsideDown) && (toOrientation == UIInterfaceOrientationLandscapeRight)))
    {

    }
    if(((fromOrientation == UIInterfaceOrientationLandscapeLeft) && (toOrientation == UIInterfaceOrientationPortraitUpsideDown))
       || ((fromOrientation == UIInterfaceOrientationLandscapeRight) && (toOrientation == UIInterfaceOrientationPortrait)))
    {

    }
    if(((fromOrientation == UIInterfaceOrientationPortrait) && (toOrientation == UIInterfaceOrientationPortraitUpsideDown))
       || ((fromOrientation == UIInterfaceOrientationPortraitUpsideDown) && (toOrientation == UIInterfaceOrientationPortrait)))
    {

    }
    if(((fromOrientation == UIInterfaceOrientationLandscapeLeft) && (toOrientation == UIInterfaceOrientationLandscapeRight))
       || ((fromOrientation == UIInterfaceOrientationLandscapeRight) && (toOrientation == UIInterfaceOrientationLandscapeLeft)))
    {

    }   
}

which seems like a perfectly good waste of code. Furthermore, I was planning on using CGAffineTransform (like cited here: http://www.crystalminds.nl/?p=1102) but I'm confused about whether I should change the view's dimensions to match what they will be after the rotation.

The big nightmare here is that you have to keep track of a global "orientation" variable. If you don't, the illusion is lost and the ViewController is rotated into whatever.

I could really use some help on this, thanks!

The best thing you can do is to change the frames of ur subview frames according to ur interface orientations. You can do it like:

 #pragma mark -
 #pragma mark InterfaceOrientationMethods

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown || interfaceOrientation == UIInterfaceOrientationLandscapeRight || interfaceOrientation == UIInterfaceOrientationLandscapeLeft);
}

//--------------------------------------------------------------------------------------------------------------------------------------------------------------------

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration{
    [super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
    if(toInterfaceOrientation == UIInterfaceOrientationPortrait || toInterfaceOrientation == UIInterfaceOrientationPortraitUpsideDown){
        //self.view = portraitView;
        [self changeTheViewToPortrait:YES andDuration:duration];

    }
    else if(toInterfaceOrientation == UIInterfaceOrientationLandscapeRight || toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft){
        //self.view = landscapeView;
        [self changeTheViewToPortrait:NO andDuration:duration];
    }
}

//--------------------------------------------------------------------------------------------------------------------------------------------------------------------

- (void) changeTheViewToPortrait:(BOOL)portrait andDuration:(NSTimeInterval)duration{

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:duration];

    if(portrait){
        //change the view and subview frames for the portrait view
    }
    else{   
        //change the view and subview  frames for the landscape view
    }

    [UIView commitAnimations];
}

Hope this helps.

i realised something.. let's say our project have multiple layer of ViewController (as in if you add subview of other view controller to your view controller)

willRotateToInterfaceOrientation:duration method will not be called for the 2nd layer of ViewController...

so what i did was, after i initialise my 2nd layer view controller from my top most layer, then when willRotateToInterfaceOrientation:duration method is called on the top-most layer, i will call willRotateToInterfaceOrientation:duration for 2nd layer view controller as well