【ASP.NET】获取服务器文件夹内所有文件，并生成下载链接

后台C#代码

protected string OUT()        {            string shtml=string.Empty;            //拼接字符串形成<p><a href='/go.html?url=/Attachment/MYSQL_多表查询学习.txt'>MYSQL_多表查询学习.txt</a></p>            string a = "<p><a href='/go.html?url=/Attachment/";            foreach (string item in Directory.GetFiles(Server.MapPath("/Attachment/"))) //获取服务器中相对路径            {                string filename = item.Substring(item.LastIndexOf("\") + 1); //获取文件名                string b = filename;                string c = "'>"+filename+"</a></p>";                shtml += a + b + c;            }            return shtml;        }protected string OUT()        {