c# 将两个表的有效数据合到一个表中

 <asp:DropDownList ID="ddlSpecialty" runat="server"  >

 </asp:DropDownList>

 　　　　　　　　　DataTable dt2 ;
                DataTable dt1 ;

                 DataTable newDt = new DataTable();
                 newDt.Columns.Add("Name", typeof(string));
                 newDt.Columns.Add("Code", typeof(string));

                foreach (DataRow dr in dt1.Rows)
                {
                    var dataRow = newDt.NewRow();
                    dataRow[] = dr["ItemName"];
                    dataRow[] = dr["ItemCode"];
                    newDt.Rows.Add(dataRow);
                }
                foreach (DataRow dr in dt2.Rows)
                {
                   var dataRow = newDt.NewRow();
                    dataRow[] = dr["ItemName"];
                    dataRow[] = dr["ItemCode"];
                    newDt.Rows.Add(dataRow);
                }
                this.ddlSpecialty.DataTextField = "Name";
                this.ddlSpecialty.DataValueField = "Code";
                this.ddlSpecialty.DataSource = newDt;
                this.ddlSpecialty.DataBind();