iOS7中UILabel高度调整注意事项

    CGSize constraint = CGSizeMake(230, 1000);
    UILabel *lbl = [[UILabel alloc]init];
    UIFont *font =[UIFont fontWithName:lbl.font.familyName size:16];
    NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:font,NSFontAttributeName, nil];
    
    CGSize size = [self.movieCommentModel.content boundingRectWithSize:constraint options:NSStringDrawingUsesLineFragmentOrigin |NSStringDrawingUsesFontLeading  attributes:dic context:nil].size;
    _content.frame = CGRectMake(20, 25, 230, ceil(size.height));