string sql_filelist = "";
        SqlParameter[] cmd_filelist =new SqlParameter[1];
        if (Request.QueryString["pdid"]!=null)
        {
             sql_filelist = "select Pid,Ptitle,Pcontent,Pnum,Psize,Pprice,PDID,PDN,PXID,PXN,dpic,Ppic,Paddtime from ProductList where PDID=@PDID order by Pid desc";
             cmd_filelist={ new SqlParameter("@PDID", Request.QueryString["pdid"]) };
        }
        if (!string.IsNullOrEmpty(Request.QueryString["pxid"]))
        {
             sql_filelist = "select Pid,Ptitle,Pcontent,Pnum,Psize,Pprice,PDID,PDN,PXID,PXN,dpic,Ppic,Paddtime from ProductList where PxID=@PxID order by Pid desc";
           cmd_filelist ={ new SqlParameter("@PxID", Request.QueryString["PxID"]) };
        }
        if (!string.IsNullOrEmpty(Request.QueryString["pbid"]))
        {
             sql_filelist = "select Pid,Ptitle,Pcontent,Pnum,Psize,Pprice,PDID,PDN,PXID,PXN,dpic,Ppic,Paddtime from ProductList where PBrandID=@PbID order by Pid desc";
             cmd_filelist ={ new SqlParameter("@PbID", Request.QueryString["PbID"]) };
        }

这样写老是报多了"}" ，不知道为什么？