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jQueryJSON 无刷新三级联动

作者: zengxiangzhan  来源: 博客园  发布时间: 2010-02-22 11:07  阅读: 2282 次  推荐: 0   原文链接   [收藏]  

曾祥展

曾祥展

<asp:DropDownList ID="ddl1" runat="server" Width="100px" ></asp:DropDownList>
<asp:DropDownList ID="ddl2" runat="server" Width="100px" ></asp:DropDownList>
<asp:DropDownList ID="ddl3" runat="server" Width="100px" ></asp:DropDownList>

js:

<script src="js/jquery-1.4.2.min.js" type="text/javascript" ></script> 
<script type="text/javascript">

$(document).ready(
function () {
GetA();
$(
"#ddl1").change(function () { GetB(); });
$(
"#ddl2").change(function () { GetC(); });
});

function GetA()
{
$(
"#ddl1").html("");
$(
"#ddl1").append("<option value='-1' selected='selected'>请选择...</option>");
//$("select[name$=ddl1] > option:selected").remove();
var strId = 0;
$.getJSON(
"LoadClass.ashx?ddlId=" + strId, function (data) {
for (var i = 0; i < data.length; i++) {
$(
"select[name$=ddl1]").append($("<option></option>").val(data[i].ID).html(data
[i].Cname));
};
GetB();
});

}
function GetB()
{
$(
"#ddl2").html(""); $("#ddl3").html("");
var strId = $("#ddl1").attr("value");
if (strId != 0) {
$.getJSON(
"LoadClass.ashx?ddlId=" + strId, function (data) {
for (var i = 0; i < data.length; i++) {
$(
"select[name$=ddl2]").append($("<option></option>").val(data[i].ID).
html(data[i].Cname));
};
GetC();
});
}
}
function GetC()
{
$(
"#ddl3").html("");
var strId = $("#ddl2").attr("value");
if (strId != 0) {
$.getJSON(
"LoadClass.ashx?ddlId=" + strId, function (data) {
for (var i = 0; i < data.length; i++) {
$(
"select[name$=ddl3]").append($("<option></option>").val(data[i].ID).
html(data[i].Cname));
};
});
}
}
</script>

LoadClass.ashx:

<%@ WebHandler Language="C#" Class="LoadClass" %>

using System;
using System.Web;

using System.Text;
using System.Data;

public class LoadClass : IHttpHandler {

public void ProcessRequest (HttpContext context) {
// 数组 [{"ID":"275","Cname":"A1"},{"ID":"319","Cname":"A2"},{"ID":"322","Cname":"
A3"}]

int strId = Convert.ToInt32(context.Request["ddlId"]);
string strSQL = "select * from Class where parent_Ptr=" + strId + " order by class
Order asc
";
db d
= new db();
DataTable dt
= d.getDT(strSQL);
StringBuilder strClass
= new StringBuilder();
if (dt != null)
{
strClass.Append(
"[");
for (int i = 0; i < dt.Rows.Count; i++)
{
strClass.Append(
"{");
strClass.Append(
"\"ID\":\"" + dt.Rows[i]["id"].ToString() + "\",");
strClass.Append(
"\"Cname\":\"" + dt.Rows[i]["classCname"].ToString() + "\"");

if (i != dt.Rows.Count - 1)
{
strClass.Append(
"},");
}
}
}
strClass.Append(
"}");
strClass.Append(
"]");
context.Response.ContentType
= "application/json";
context.Response.ContentEncoding
= Encoding.UTF8;
context.Response.Write(strClass.ToString());
context.Response.End();
}
public bool IsReusable {
get {
return false;
}
}
}

注意:

代码
//后台只能获取value值,不能直接获取text,需要通过js、控件中转
//结果:275 276 277
Label1.Text = Request.Form[ddl1.UniqueID] + " "
+ Request.Form["ddl2"] + " "
+ Request.Form[ddl3.ClientID.Replace("_", "$")] ;

遇到的问题:下拉框text的值通过HiddenField控件中转

<asp:HiddenField ID="HiddenField1" runat="server" />
<asp:HiddenField ID="HiddenField2" runat="server" />
<asp:HiddenField ID="HiddenField3" runat="server" />

把选中下拉框的值赋予隐藏控件中:

<script type="text/javascript">
var Key1 = $("#ddl1>option:selected").val();
$(
'#HiddenField1').val(Key1);
var Key2 = $("#ddl2>option:selected").val();
$(
'#HiddenField2').val(Key2);
var Key3 = $("#ddl3>option:selected").val();
$(
'#HiddenField3').val(Key3);
</script>

选择下拉框后 动态赋值到HiddenField 控件中的值 无法与下拉框选中的值相对应!可能与初始化有关,赋值这段代码应该放到什么地方呢?或者有什么好的方法,欢迎讨论?

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标签:jQuery JSON

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