利用 NSTextStorage\NSTextLayout\NSTextContainer 初始化 UITextView 时 textview 不能滚动问题

[lcl22hope]

scrollEnabled 已经 Yes，超出部分无法滚动查看，是我哪里用错了么？求教
参考这篇文章，实现的缩进 http://www.ituring.com.cn/tupubarticle/2542
CGRect textViewRect = CGRectInset(_layerView.bounds, 5, 5);
_textStorage = [[NSTextStorage alloc] initWithString:text];
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
[_textStorage addLayoutManager:layoutManager];
_textContainer = [[NSTextContainer alloc] initWithSize:textViewRect.size];
[layoutManager addTextContainer:_textContainer];
[_contentEditView removeFromSuperview];
_contentEditView = [[UITextView alloc] initWithFrame:textViewRect textContainer:_textContainer];
_contentEditView.backgroundColor = [UIColor purpleColor];
_contentEditView.layer.cornerRadius = 5;
_contentEditView.layer.masksToBounds = YES;
_contentEditView.font = HIRAGINO_SANSGB_W3_FONT;
[_contentEditView setShowsHorizontalScrollIndicator:NO];
_contentEditView.delegate = self;
[_layerView addSubview:_contentEditView];

[Galvin]

textview的contentsize 输出一下看看？也许某些地方没有让textview内容自适应？