GridView 实现LinkButton下载文件/附件

  <asp:TemplateField  >
           <ItemTemplate>
                 <asp:LinkButton ID="lbtnDownFile" runat="server" CommandName="DownFile" CommandArgument='<%# Eval("UFID") %>' >下载</asp:LinkButton>
           </ItemTemplate>

</asp:TemplateField>

protected void gdvwUpFile_RowCommand(object sender, GridViewCommandEventArgs e)
    {

        if (e.CommandName== "DownFile")
        {
            int id = int.Parse(e.CommandArgument.ToString());

            DataBase db = new DataBase();
            string sqlDown = "select  UFFileName from  PTestUploadFiles where UFID=" + id+"";
            DataTable dt= db.GetDataSet(sqlDown).Tables[];

            string fileName = dt.Rows[][].ToString();
            string filePath = Server.MapPath("/UpFile/"+fileName);

            FileStream fs = new FileStream(filePath, FileMode.Open);
            byte[] bytes = new byte[(int)fs.Length];
            fs.Read(bytes, , bytes.Length);
            fs.Close();
            Response.ContentType = "application/octet-stream";
            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
            Response.BinaryWrite(bytes);
            Response.Flush();
            Response.End();

        }
    }