uitextview 最后一行遮挡

这只 uiscrollerview 的 setContentOffset

CGRect line = [textView caretRectForPosition:
                       textView.selectedTextRange.start];
        CGFloat overflow = line.origin.y + line.size.height
        - ( textView.contentOffset.y + textView.bounds.size.height
           - textView.contentInset.bottom - textView.contentInset.top);
        if ( overflow >  ) {
            // We are at the bottom of the visible text and introduced a line feed, scroll down (iOS 7 does not do it)
            // Scroll caret to visible area
            CGPoint offset = textView.contentOffset;
            offset.y += overflow + ; // leave 7 pixels margin
            // Cannot animate with setContentOffset:animated: or caret will not appear
//            [UIView animateWithDuration:.2 animations:^{
//                [textView setContentOffset:offset];
//            }];
            [textView setContentOffset:offset];
        }