//取图片
            MatchCollection   matchs   =   Regex.Matches(AskText,@" ]*src=([""']*)(?[^'""]*)\1[^>]*>", RegexOptions.IgnoreCase);
            List PicArray=new List();
            foreach (Match m in matchs)
            {
             
                     PicArray.Add(m.Groups["src"].Value); 
              
            }

//取汉字

ListAskText = Regex.Replace(AskText, @"[^\u4e00-\u9fa5]", "");