How to change superview of uiscrollview?

i have a big uiscrollview and topView in ipad viewcontroller, leftscrollView and topView.开发者_如何学运维

there are child scrollviews in leftScrollView. i want to move a childscrollview into topView .

i couldnt cahnge the superview. it says its readonly.

how can i swap it to another view?

[topView addSubview:childScrollView];