Ajax中怎么实现无刷新三联动下拉框功能

发布时间：2021-08-07 16:58:50 作者：Leah
来源：亿速云阅读：139

Ajax中怎么实现无刷新三联动下拉框功能，很多新手对此不是很清楚，为了帮助大家解决这个难题，下面小编将为大家详细讲解，有这方面需求的人可以来学习下，希望你能有所收获。

<HTML>
<HEAD>
<title>Ajax实现无刷新三联动下拉框</title>
<meta content="Microsoft Visual Studio .NET 7.1" name="GENERATOR">
<meta content="C#" name="CODE_LANGUAGE">
<meta content="JavaScript" name="vs_defaultClientScript">
<meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
<SCRIPT language="javascript">
//城市------------------------------
function cityResult()
{
var city=document.getElementById("DropDownList1");
AjaxMethod.GetCityList(city.value,get_city_Result_CallBack);
}

function get_city_Result_CallBack(response)
{
if (response.value != null)
{
//debugger;
document.all("DropDownList2").length=0;　　　　
　　　　 var ds = response.value;
if(ds != null && typeof(ds) == "object" && ds.Tables != null)
{
for(var i=0; i<ds.Tables[0].Rows.length; i++)
　　　　 {
　　　　 var name=ds.Tables[0].Rows[i].city;
　　　　　　 var id=ds.Tables[0].Rows[i].cityID;
　　　　　　 document.all("DropDownList2").options.add(new Option(name,id));
　　　　 }
}
}
return
}
//市区----------------------------------------
function areaResult()
{
var area=document.getElementById("DropDownList2");
AjaxMethod.GetAreaList(area.value,get_area_Result_CallBack);
}
function get_area_Result_CallBack(response)
{
if (response.value != null)
{
document.all("DropDownList3").length=0;　　　　
　　　　 var ds = response.value;
if(ds != null && typeof(ds) == "object" && ds.Tables != null)
{
for(var i=0; i<ds.Tables[0].Rows.length; i++)
　　　　 {
　　　　　　 var name=ds.Tables[0].Rows[i].area;
　　　　　　 var id=ds.Tables[0].Rows[i].areaID;
　　　　　　 document.all("DropDownList3").options.add(new Option(name,id));
　　　　 }
}
}
return
}
function getData()
{
var province=document.getElementById("DropDownList1");
var pindex = province.selectedIndex;
var pValue = province.options[pindex].value;
var pText = province.options[pindex].text;

var city=document.getElementById("DropDownList2");
var cindex = city.selectedIndex;
var cValue = city.options[cindex].value;
var cText = city.options[cindex].text;

var area=document.getElementById("DropDownList3");
var aindex = area.selectedIndex;
var aValue = area.options[aindex].value;
var aText = area.options[aindex].text;

var txt=document.getElementById("TextBox1");

document.getElementById("<%=TextBox1.ClientID%>").innerText="省:"+pValue+"|"+pText+"市:"+cValue+"|"+cText+"区:"+aValue+"|"+aText;
}
</SCRIPT>
</HEAD>
<body ms_positioning="GridLayout">
<form id="Form1" method="post" runat="server">
<TABLE id="Table1" cellSpacing="1"
cellPadding="1" width="300" border="1" bgColor="#ccff66">
<TR>
<TD>省市</TD>
<TD><asp:dropdownlist id="DropDownList1" runat="server"></asp:dropdownlist></TD>
</TR>
<TR>
<TD>城市</TD>
<TD><asp:dropdownlist id="DropDownList2" runat="server"></asp:dropdownlist></TD>
</TR>
<TR>
<TD>市区</TD>
<TD><asp:dropdownlist id="DropDownList3" runat="server"></asp:dropdownlist></TD>
</TR>
</TABLE>
<asp:TextBox id="TextBox1" runat="server"
Width="424px"></asp:TextBox><INPUT
type="button" value="test" onclick="getData();">
</form>
</body>
</HTML>

2.cs代码
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace AjaxTest
{
/**//// <summary>
/// Summary description for WebForm1.
/// </summary>
public class WebForm1 : System.Web.UI.Page
{
protected System.Web.UI.WebControls.DropDownList DropDownList1;
protected System.Web.UI.WebControls.DropDownList DropDownList2;
protected System.Web.UI.WebControls.TextBox TextBox1;
protected System.Web.UI.WebControls.DropDownList DropDownList3;

private void Page_Load(object sender, System.EventArgs e)
{
Ajax.Utility.RegisterTypeForAjax(typeof(AjaxMethod));
if(!Page.IsPostBack)
{
this.DropDownList1.DataSource=AjaxMethod.GetProvinceList();
this.DropDownList1.DataTextField="province";
this.DropDownList1.DataValueField="provinceID";
this.DropDownList1.DataBind();

this.DropDownList1.Attributes.Add("onclick","cityResult();");
this.DropDownList2.Attributes.Add("onclick","areaResult();");
}
}

Web Form Designer generated code#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}

/**//// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);

}
#endregion
}
}

3.AjaxMethod
using System;
using System.Data;
using System.Data.SqlClient;
namespace AjaxTest
{
/**//// <summary>
/// Summary description for AjaxMethod.
/// </summary>
public class AjaxMethod
{
GetProvinceList#region GetProvinceList
public static DataSet GetProvinceList()
{
string sql="select * from province";
return GetDataSet(sql);
}
#endregion

GetCityList#region GetCityList
[Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
public DataSet GetCityList(int provinceid)
{
string sql="select * from city where father="+provinceid;
return GetDataSet(sql);
}
#endregion

GetAreaList#region GetAreaList
[Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
public DataSet GetAreaList(int cityid)
{
string sql="select * from area where father="+cityid;
return GetDataSet(sql);
}
#endregion

GetDataSet#region GetDataSet
public static DataSet GetDataSet(string sql)
{
string ConnectionString=System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"];
SqlDataAdapter sda =new SqlDataAdapter(sql,ConnectionString);
DataSet ds=new DataSet();
sda.Fill(ds);
return ds;
}
#endregion
}
}

4.web.config
<httpHandlers>
<add verb="POST,GET" path="ajax/*.ashx" type="Ajax.PageHandlerFactory, Ajax" />
</httpHandlers>5.ajax.dll下载/Files/singlepine/Ajax.rar

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Ajax中怎么实现无刷新三联动下拉框功能

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