.NET------ 将文本框变成下拉框

       <td  style="white-space: nowrap" align="right">&nbsp;专业名称：
            
         <asp:TextBox ID="tbsqlZhuanYeName" runat="server" style="width:121px"></asp:TextBox><img src="../../qdadmin/qdimages/wherenot.png" align="top">
</td>

        {//专业
              //  private ITEM.Inherits.Bll.qdMis4.bllBZhuanYe _bllZhuanYe = new bllBZhuanYe();
            List<ITEM.Model.qdMis4.BZhuanYe> mList = _bllZhuanYe.GetListSelBZhuanYe3("ZhuanYeGuid,ZhuanYeName", base.EnterpriseGuid);
            if (mList.Count <= 0)
            { this.ddlsqlZhuanYeGuid.Visible = false; this.tbsqlZhuanYeName.Visible = true; }
            else { this.ddlsqlZhuanYeGuid.Visible = true; this.tbsqlZhuanYeName.Visible = false; }
            this.ddlsqlZhuanYeGuid.DataTextField = "ZhuanYeName";
            this.ddlsqlZhuanYeGuid.DataValueField = "ZhuanYeGuid";
            this.ddlsqlZhuanYeGuid.DataSource = mList;
            this.ddlsqlZhuanYeGuid.DataBind();
            this.ddlsqlZhuanYeGuid.Items.Insert(0, new ListItem());
        }

      if (ddlsqlZhuanYeGuid.SelectedValue != string.Empty)
        {
            cclass.ZhuanYeGuid = ddlsqlZhuanYeGuid.SelectedValue;
            cclass.ZhuanYeName = ddlsqlZhuanYeGuid.SelectedItem.Text;
        }
        else {

            WebMessageBox1.MessageBox_tishi(700, 300, 200, 300, "请选择专业"); return;
        }

        if (this.ddlsqlZhuanYeGuid.Visible == true)
        {
            if (this.ddlsqlZhuanYeGuid.SelectedValue != string.Empty)//专业GUID
            {
                strSql += " and ZhuanYeGuid=‘" + this.ddlsqlZhuanYeGuid.SelectedValue + "‘";
            }
        }
        else
        {
            if (this.tbsqlZhuanYeName.Text.Trim() != string.Empty)//专业name
            {
                strSql += " and ZhuanYeName=‘" + this.tbsqlZhuanYeName.Text.Trim() + "‘";
            }
        }

            //回显

            if (this.ddlsqlZhuanYeGuid.Visible == true)
                this.ddlsqlZhuanYeGuid.SelectedValue = cclass.ZhuanYeGuid.ToString();//专业
            else
                this.tbsqlZhuanYeName.Text = cclass.ZhuanYeName.ToString();//专业