gridview中Combox怎么設定默認值

protected void gv_EmpInfor_RowDataBound(object sender, GridViewRowEventArgs e)    {        if (e.Row.RowType == DataControlRowType.DataRow)        {            if (e.Row.RowState == DataControlRowState.Alternate || e.Row.RowState == DataControlRowState.Normal)            {                GridViewRow drv = e.Row;                //首級部門的代號                string sparentcode = ((System.Data.DataRowView)(drv.DataItem)).Row.ItemArray[9].ToString();                //首級部門的編碼                 string sPartDeptcode = ((System.Data.DataRowView)(drv.DataItem)).Row.ItemArray[10].ToString();                //職位表中的職位編碼                string stechcode = ((System.Data.DataRowView)(drv.DataItem)).Row.ItemArray[8].ToString();                //員工表中的架構職位代碼                string sEmpTechcode = ((System.Data.DataRowView)(drv.DataItem)).Row.ItemArray[6].ToString();                //如果員工表中架構職位代碼為空則自動綁定初始部門，子部門，職位并生成編碼。                //首級部門控件                Control control = e.Row.FindControl("rcb_ParentDept");                if (control != null)                {                    DropDownList rcb_firstdept = control as DropDownList;                    rcb_firstdept.DataSource = GetParentDept();                                        rcb_firstdept.DataTextField = "departmentname";                    rcb_firstdept.DataValueField = "PartDeptCode";                    rcb_firstdept.DataBind();                    rcb_firstdept.Items.Insert(0, new ListItem("請選擇", "-1"));                   // rcb_firstdept.SelectedItem.Text = "集團";                    rcb_firstdept.Attributes.Add("RowIndex", e.Row.RowIndex.ToString());                    if (sEmpTechcode == string.Empty)                    {//此項是關鍵-----我設置了這項值可顯示的值還是“請選擇”                        rcb_firstdept.SelectedItem.Value = "00002$FA";// sparentcode + "$" + sPartDeptcode;                       // rcb_firstdept.SelectedIndex = rcb_firstdept.Items.IndexOf(new ListItem("生產部"));                    }                }                //子部門控件                Control control1 = e.Row.FindControl("rcb_SubDept");                if (control != null)                {                    DropDownList rcb_subDept = control1 as DropDownList;                    rcb_subDept.Attributes.Add("RowIndex", e.Row.RowIndex.ToString());                }                //職位列表控件                Control control2 = e.Row.FindControl("rcb_Technical");                if (control != null)                {                    DropDownList rcb_tchnical = control2 as DropDownList;                    rcb_tchnical.Attributes.Add("RowIndex", e.Row.RowIndex.ToString());                }            }        }    }