iOS UILabel自適應高度

-(CGSize)sizeWithString:(NSString *)string font:(UIFont *)font

{
    CGRect rect = [string boundingRectWithSize:CGSizeMake(320, 8000)//限制最大的寬度和高度
                                       options:NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesFontLeading  |NSStringDrawingUsesLineFragmentOrigin//採用換行模式
                                    attributes:@{NSFontAttributeName: font}//傳人的字體字典
                                       context:nil];
     
    return rect.size;
}

原文鏈接：https://segmentfault.com/a/1190000003409601