UITextView作为内容文本输入区域，有的时候我们需要根据内容动态改变文本区域的高度，效果如下:

定义UITextView，实现UITextViewDelegate:

-(UITextView *)textView{    if (!_textView) {        //http://www.cnblogs.com/xiaofeixiang/        _textView=[[UITextView alloc]initWithFrame:CGRectMake(30, 200, CGRectGetWidth([[UIScreen mainScreen] bounds])-60, 30)];        [_textView setTextColor:[UIColor redColor]];        [_textView.layer setBorderColor:[[UIColor blackColor] CGColor]];        [_textView setFont:[UIFont systemFontOfSize:15]];        [_textView.layer setBorderWidth:1.0f];        [_textView setDelegate:self];    }    return _textView;}

实现textViewDidChange方法:

-(void)textViewDidChange:(UITextView *)textView{    //博客园-FlyElephant    static CGFloat maxHeight =60.0f;    CGRect frame = textView.frame;    CGSize constraintSize = CGSizeMake(frame.size.width, MAXFLOAT);    CGSize size = [textView sizeThatFits:constraintSize];    if (size.height<=frame.size.height) {        size.height=frame.size.height;    }else{        if (size.height >= maxHeight)        {            size.height = maxHeight;            textView.scrollEnabled = YES;   // 允许滚动        }        else        {            textView.scrollEnabled = NO;    // 不允许滚动        }    }    textView.frame = CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, size.height);}