DropdownList总结

dropdownlist在后台从数据库中读取赋值：

    //仓库名称下拉框的值
    DataSet ds = stock.GetNameInfo(); 
    DataTable dtWarehouseName = ds.Tables[0];
    DataRow drWarehouseName = dtWarehouseName.NewRow();

    drWarehouseName["WarehouseName"] = "请选择";
    drWarehouseName["WarehouseID"] = "0";
    dtWarehouseName.Rows.InsertAt(drWarehouseName, 0);
    dtWarehouseName.AcceptChanges();

    ddlWarehouse.DataSource = dtWarehouseName;
    ddlWarehouse.DataTextField = "WarehouseName";
    ddlWarehouse.DataValueField = "WarehouseID";
    ddlWarehouse.DataBind();

手动添加项：
 DropDownList ddl = new DropDownList();
        ddl.Items.Add(new ListItem("北京", "1"));
        ddl.Items.Add(new ListItem("上海", "2"));
        ddl.Items.Add(new ListItem("广州", "3"));

 

在后台选中Dropdownlist的某一项
  ListItem item = list.Items.FindByText("设备发放库");
        if (item != null) item.Selected = true;

 

            var ddlUseType = document.getElementById('<%=ddlUseType.ClientID %>'); //用途类别
            var ddlUseTypeValue = ddlUseType.options[ddlUseType.selectedIndex].value;
            if (ddlUseTypeValue == "0" && btnID != "btn1" && btnID != "btn8") {
                openAlertDialog("请选择用途类别！");
                return false;
            }

if ($("#ddlUseType").val() == "0" && btnID != "btn1" && btnID != "btn8") {
                openAlertDialog("请选择业务类别！");
                return false;
            }

if ($("#ddlUseType").find(":selected").text() == "请选择" && btnID != "btn1" && btnID != "btn8") {
                openAlertDialog("请选择用途类别！");
                return false;
            }