jQuery JSON实现无刷新三级联动实例探讨_jquery

js:

LoadClass.ashx:

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 classOrder asc ";
db d = new db();
DataTable dt = d.getDT(strSQL);
StringBuilder strClass = new StringBuilder();
if (dt != null)
{
strClass.Append("[");
for (int i = 0; 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：

//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


把选中下拉框的值赋予隐藏控件中：

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？