基于jquery ajax实现DropDownList二级联动

using System.Web.Services;
// 实现下拉框二级联动AJAX请求加载数据方法
[WebMethod()]
public static ArrayList GetSubList(string sBuyID)
{
ArrayList subList = new ArrayList();

if (sBuyID == "1")
{
subList.Add(new ListItem("文艺", "1"));
subList.Add(new ListItem("少儿", "2"));
subList.Add(new ListItem("人文社科", "3"));
subList.Add(new ListItem("科技", "4"));
}
else if (sBuyID == "2")
{
subList.Add(new ListItem("手机通讯", "1"));
subList.Add(new ListItem("手机配件", "2"));
subList.Add(new ListItem("摄影摄像", "3"));
subList.Add(new ListItem("数码配件", "4"));
}

return subList;
}

function sendData(sBuyID) {
var loc = window.location.href;
$.ajax({
type: "POST",
url: loc + "/GetSubList", // 调动后台页面方法
data: '{"sBuyID":"' + sBuyID + '"}',
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (msg) {
// msg.d是数组，由后台数组ArrayList返回，因此可以遍历每个元素
$.each(msg.d, function () {
// this.Value和this.Text是后台返回数组ArrayList类型包含元素ListItem类型的属性
$("#subList").append($(" });
},
error: function () {
alert("ajax请求发生错误");
}
});
}
});