具体实现方法如下：

string dirPath = HttpContext.Current.Server.MapPath("uploads/");if (Directory.Exists(dirPath)){       //获得目录信息       DirectoryInfo dir = new DirectoryInfo(dirPath);       //获得目录文件列表       FileInfo[] files = dir.GetFiles("*.*");       string[] fileNames = new string[files.Length];
       //临时数据表       DataTable dt = new DataTable();       dt.Columns.Add("FileName");              foreach (FileInfo fileInfo in files)       {    DataRow dr = dt.NewRow();    dr["FileName"] = fileInfo.Name;    dt.Rows.Add(dr);
       }       Repeater1.DataSource = dt;       Repeater1.DataBind();}
if (e.CommandName == "down"){    try    {     string DownloadFileName = "~/uploads/" + e.CommandArgument.ToString();//文件路径     string filepath = Server.MapPath(DownloadFileName);     string filename = Path.GetFileName(filepath);     FileInfo file = new FileInfo(filepath);     Response.Clear();     Response.ContentType = "application/octet-stream";     Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8));     Response.AddHeader("Content-length", file.Length.ToString());     Response.Flush();     Response.WriteFile(filepath);    }    catch    { Response.Write("");    }}