ScrollView scroll to center point.

ScrollViewCenter

CGRect visibleRect = CGRectMake(0, 0, self.scrollView.contentSize.width, self.scrollView.contentSize.height);
    CGRect centeredRect = CGRectMake(visibleRect.origin.x + visibleRect.size.width/2.0 - self.scrollView.frame.size.width/2.0,
                                     visibleRect.origin.y + visibleRect.size.height/2.0 - self.scrollView.frame.size.height/2.0,
                                     self.scrollView.frame.size.width,
                                     self.scrollView.frame.size.height);
    [self.scrollView scrollRectToVisible:centeredRect animated:NO];