ajax2级联动，遇到一个异步优先级问题，使用settimeout 解决
页面:
Code<%@ Control Language="C#" AutoEventWireup="true" CodeFile="AreaSelect.ascx.cs" Inherits="CorpUserRegister_AreaSelect" %>
<script type="text/javascript">
function getDiqu()
{
var cityID = document.getElementById("AreaSelect1_drp_Chengshi").value;
CorpUserRegister_AreaSelect.getDiqu(cityID,getDiquRes);
}
function getDiquRes(res)
{
if(res.value != null)
{
var dt = res.value;
var ddlQu = document.getElementById("AreaSelect1_drp_Qu");
if(dt != null && typeof(dt) == "object")
{
//清理列表项
ddlQu.length=0;
ddlQu.options.add(new Option('请选择','-1'));
for(var i = 0;i < dt.Rows.length;i++)
{
var name = dt.Rows[i].Title;
var id = dt.Rows[i].SortCode;//这里对应数据表中的字段名
ddlQu.options.add(new Option(name,id));
}
}
else
{
ddlQu.options.add(new Option("数据读取错误，请刷新页面",-1));
}
}
}
var ddl ;
var theIndex;
var theValue;
var theText;
function postDiqu()
{
var a = new Array(4);
getElem("AreaSelect1_drp_Chengshi");
a[0]=theText;
a[1]=theValue;
getElem("AreaSelect1_drp_Qu");
a[2]= theText;
a[3]=theValue;
var hiddenValue = document.getElementById('AreaSelect1_HiddenValue').value=a;
document.getElementById('AreaSelect1_HiddenCityName').value=a[0];
document.getElementById('AreaSelect1_HiddenCityID').value=a[1];
document.getElementById('AreaSelect1_HiddenQuName').value=a[2];
document.getElementById('AreaSelect1_HiddenQuID').value=a[3];
CorpUserRegister_AreaSelect.postDiqu(a,postDiquRes);
}
function postDiquRes(res)
{
//alert(res.value);
}
function getElem(obj)
{
ddl = document.getElementById(obj);
theIndex = ddl.selectedIndex;
theValue = ddl.options[theIndex].value;
theText = ddl.options[theIndex].text;
}
onload=function()
{
var isPostChengshi = document.getElementById('AreaSelect1_HiddenCityID').value;
getElem("AreaSelect1_drp_Chengshi");
for(i=0;i<ddl.options.length;i++)
{
if(ddl.options[i].value==isPostChengshi)
{
ddl.selectedIndex = i;
}
}
if(isPostChengshi>0)
{
getDiqu();
//延时等待获取2级列表完成,即使时间设置为0也是必须有的，是为了降低异步排序优先级 20090617
setTimeout(getPostBackQu,0);
}
else
{
getPostBackQu();
}
}
function getPostBackQu()
{
var isPostBackQu = document.getElementById('AreaSelect1_HiddenQuID').value;
getElem("AreaSelect1_drp_Qu");
for(i=0;i<ddl.options.length;i++)
{
if(ddl.options[i].value==isPostBackQu)
{
ddl.selectedIndex = i;
}
}
}
</script>
<asp:DropDownList runat="server" ID="drp_Chengshi">
<asp:ListItem Value="-1">选择</asp:ListItem>
</asp:DropDownList>
<asp:DropDownList ID="drp_Qu" ckCode="10" runat="server" CssClass="sample" flow="1">
</asp:DropDownList>
<asp:HiddenField ID="HiddenValue" runat="server" />
<asp:HiddenField ID="HiddenCityName" runat="server" />
<asp:HiddenField ID="HiddenCityID" runat="server" />
<asp:HiddenField ID="HiddenQuName" runat="server" />
<asp:HiddenField ID="HiddenQuID" runat="server" />
cs:
Codeusing System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
/// <summary>
/// 使用说明
///
/// 若要获取整个字符串
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenValue"))).Value
/// 获取到的字符串分别依次是 城市名,城市id,区县名,区县ID，请split
///
/// 若需要独立的值
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenCityName"))).Value
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenCityID"))).Value
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenQuName"))).Value
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenQuID"))).Value
///
/// 若要给dropdowlist赋初始值：在隐藏域中赋值，会被dropdownlist获取到
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenCityName"))).Value = 值
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenCityID"))).Value = 值
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenQuName"))).Value = 值
/// ((HiddenField)(this.AreaSelect1.FindControl("HiddenQuID"))).Value = 值
/// </summary>
public partial class CorpUserRegister_AreaSelect : System.Web.UI.UserControl
{
////通过protected的变量，向page传递参数
//public string _cityName = string.Empty;
//public string _cityID = string.Empty;
//public string _cityQuName = string.Empty;
//public string _cityQuID = string.Empty;
protected void Page_Load(object sender, EventArgs e)
{
AjaxPro.Utility.RegisterTypeForAjax(typeof(CorpUserRegister_AreaSelect));
this.drp_Chengshi.Attributes.Add("onchange", "getDiqu();");
this.drp_Qu.Attributes.Add("onchange", "postDiqu();");
//取默认的城市
ViewState["S_AreaCode"] = FlowDll.GetSysDefaultAreaCode( );
if (!Page.IsPostBack)
{
bindCity();
bindQu();
}
else
{
bindQu();
}
}
private void bindCity()
{
DataView dr = new UserRegisterOp().BindDdl_Area().DefaultView;
this.drp_Chengshi.DataSource = dr;
drp_Chengshi.DataTextField = "Title";
drp_Chengshi.DataValueField = "Code";
drp_Chengshi.DataBind();
drp_Chengshi.SelectedValue = ViewState["S_AreaCode"].ToString();
drp_Chengshi.Items.Insert(0, new ListItem("选择", "-1"));
//判断本地是否可选
try
{
drp_Chengshi.Enabled = bool.Parse(System.Configuration.ConfigurationSettings.AppSettings["bLocalAreaCodeEdit"].ToString());
}
catch
{
//若没有特别定义，都可选
drp_Chengshi.Enabled = true;
}
}
/// <summary>
/// 邦定本市的区
/// </summary>
private void bindQu()
{
DataView dr = new UserRegisterOp().BindDdl_SubArea(drp_Chengshi.SelectedValue.Trim()).DefaultView;
drp_Qu.DataSource = dr;
drp_Qu.DataTextField = "title";
drp_Qu.DataValueField = "sortcode";
drp_Qu.DataBind();
drp_Qu.Items.Insert(0, new ListItem("请选择", "-1"));
}
[AjaxPro.AjaxMethod]
public DataView getDiqu(string cityID)
{
DataView dv = new UserRegisterOp().BindDdl_SubArea(cityID).DefaultView;
return dv;
}
////向公共变量中传递值
[AjaxPro.AjaxMethod]
public string postDiqu(string[] options)
{
return ViewState["diqu"].ToString();
}
}
