presentModalViewController is not work in UIScrollView

Question

I add UIViewController in UIScrollview. I add button and presentModalViewController is calling when the button press.

[self presentModalViewController:picker animated:YES];

it can't show properly and NavigationItemBar buttons are hidden in UIScrollView and navigationbar is showing in UIScrollView. I also try like that

[self.parentViewController presentModalViewController:picker animated:YES];

but no luck