// 当下拉专业改变时,添加班级信息 protected void DdlSpeciality_SelectedIndexChanged(object sender, EventArgs e) { if (ddlDepartment.SelectedValue != "null" && ddlSpeciality.SelectedValue != "null") { // 获得班级 ddlClass.Items.Clear(); // 先清空已下拉菜单 ddlClass.Items.Add(new ListItem("==请选择==", "null")); //设置第一行 ddlClass.DataSource = finSrv.GetClass(ddlSpeciality.SelectedValue); ddlClass.DataBind(); } else { lbMessage.Text = "请选择学院和专业"; } }