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?

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[topView addSubview:childScrollView];