请教把list放入dataset中的方法

我先说一下我的问题吧，我有一张报名表和一张员工表，有一个下拉框可以查找已报名和未报名的员工，但是我的员工表里面有2W人，如果我选择未报名或已报名的话，它要加载很长时间才能显示出来，请问大家有没有什么优化的方法,我写的方法如下:
//查询按钮的事件
protected void btnselect_Click(object sender, EventArgs e)
    {
        string where = "";
        tlgbpx.Model.P_XTYHB xtyhb = (tlgbpx.Model.P_XTYHB)Session["User"];
        string yhbm = xtyhb.BMBM;
        string BJID = "";
        if (Request["BJID"] != "")
        {
            BJID = Request["BJID"].ToString();
        }
        if (XMtxt.Text.Trim() != "")         //通过姓名查找
        {
            where += " and XM like '" + TYClass.StrFilter(XMtxt.Text.Trim()) + "%'";
        }
        else
        {
            if (DropDownList1.SelectedItem.Text == "已报名")        //查找已报名人员
            {
                List<tlgbpx.Model.P_BMB> listBMB = new List<P_BMB>();
                if (DWtxt.Text.Trim() != "")
                {
                    List<tlgbpx.Model.LZ_DWJBXX> listDWJBXX = tlgbpx.BLL.LZ_DWJBXX.getLiseByWHERE(" where dwmc like '" + TYClass.StrFilter(DWtxt.Text.Trim()) + "%'");
                        if (listDWJBXX.Count > 0)
                        {
                            where += " and dwbsm in(";
                            for (int i = 0; i < listDWJBXX.Count; i++)
                            {
                                where += "'" + listDWJBXX[i].DWBSM + "',";
                            }
                            where = where.Substring(0, where.Length - 1) + ")";
                        }
                }
                listBMB = tlgbpx.BLL.BMB.getListBMBByWHERE(" where BJID='" + BJID + "'");
                if (listBMB.Count > 0)
                {
                    where += " and rybm in(";
                    for (int i = 0; i < listBMB.Count; i++)
                    {
                        tlgbpx.Model.P_BMB bmb = listBMB[i];
                        where += "'" + bmb.RYBM + "',";
                    }
                    where = where.Substring(0, where.Length - 1) + ")";
                }
            }
            if (DropDownList1.SelectedItem.Text == "--请选择--")
            {
                if (DWtxt.Text.Trim() != "")
                {
                    List<tlgbpx.Model.LZ_DWJBXX> listDWJBXX = tlgbpx.BLL.LZ_DWJBXX.getLiseByWHERE(" where dwmc like '" + TYClass.StrFilter(DWtxt.Text.Trim()) + "%'");
                    if (listDWJBXX.Count > 0)
                    {
                        where += " and dwbsm in(";
                        for (int i = 0; i < listDWJBXX.Count; i++)
                        {
                            where += "'" + listDWJBXX[i].DWBSM + "',";
                        }
                        where = where.Substring(0, where.Length - 1) + ")";
                    }
                }
            }
            if (DropDownList1.SelectedItem.Text == "未报名")        //查找未报名人员
            {
                List<tlgbpx.Model.GG_ZGJBXX> listZGJBXX = new List<tlgbpx.Model.GG_ZGJBXX>();
                string acc = "";
                if (DWtxt.Text.Trim() != "")
                {
                    List<tlgbpx.Model.LZ_DWJBXX> listDWJBXX = tlgbpx.BLL.LZ_DWJBXX.getLiseByWHERE(" where dwmc like '" + TYClass.StrFilter(DWtxt.Text.Trim()) + "%'");
                        if (listDWJBXX.Count > 0)
                        {
                            acc = " and dwbsm in(";
                            for (int i = 0; i < listDWJBXX.Count; i++)
                            {
                                acc += "'" + listDWJBXX[i].DWBSM + "',";
                            }
                            acc = acc.Substring(0, acc.Length - 1) + ")";
                        }
                }
                listZGJBXX = tlgbpx.BLL.GG_ZGJBXX.getListByWHERE(" where 1=1 " + acc);
                if (listZGJBXX.Count > 0)
                {
                    string abc = "";
                    for (int i = 0; i < listZGJBXX.Count; i++)
                    {
                        tlgbpx.Model.P_BMB bmb = tlgbpx.BLL.BMB.getBMBByZGIDandBJID(listZGJBXX[i].RYBM, BJID);
                        if (bmb == null)
                        {
                            abc += "'" + listZGJBXX[i].RYBM + "',";
                        }
                    }
                    if (abc != "")
                    {
                        where += " and rybm in(" + abc.Substring(0, abc.Length - 1) + ")";
                    }
                }
            }
        }
        ViewState["where"] = where;
        YGgetdatabind(ViewState["where"].ToString());
    }//员工绑定的
    void YGgetdatabind(string where)
    {
        string strSql = " where 1=1";
        if (where != "")
        {
            strSql += where;
        }
        DataSet ds = tlgbpx.BLL.GG_ZGJBXX.getDataSet(strSql);
        DataView dv = ds.Tables[0].DefaultView;
        PagedDataSource pds = new PagedDataSource();
        AspNetPager1.RecordCount = dv.Count;
        AspNetPager1.PageSize = 15;
        pds.DataSource = dv;
        pds.AllowPaging = true;
        pds.CurrentPageIndex = AspNetPager1.CurrentPageIndex - 1;
        pds.PageSize = AspNetPager1.PageSize;
        this.GridView1.DataSource = pds;
        this.GridView1.DataBind();
    }