Half Page Curl Effect from the TOP

I am writing an iPhone app but have run into a problem with an animation effect I am trying to implementing.

I am trying to add a half page curl effect from TOP.

I am using CAAnimation of "pageCurl", with the subtype set to kCATransitionFromTop or Right. And I also tried to use UIModalTransitionStylePartialCurl of the 开发者_JAVA百科UIViewController. But it curls the page from the botton.

My main problem is how to change the transition direction, to get it to curl from the top.

Can anyone help me? I feel that stackoverflow can fix my problem.

Waiting for your replying.... Regards.

Huh. Just an idea, but what if you tried rotating the view 180 degrees so that its upside-down using a CGAffineTransform (view.transform = CGAffineTransformMakeRotation(M_PI)) or something? Maybe if the view is upside-down, the animation will also be that way. Its kind of convoluted, and you might need to do a bunch of rotations and reorganizations with subviews to make them positioned correctly and right-side-up oriented, but might work.