Scripts/Category.js
//Jquery三级类别联动 $(function () { BindCategory(); }) function BindCategory() { var $txtCategory = $("#txtCategoryId"); var _selectId = ["selBigClass", "selSmallClass", "selThreeClass"]; for (var i = 0; i < _selectId.length; i++) { var select = document.createElement("select"); select.id = _selectId[i]; select.name = _selectId[i]; $txtCategory.parent().append(select); } var $selBigClass = $("#selBigClass"); var $selSmallClass = $("#selSmallClass"); var $selThreeClass = $("#selThreeClass"); $selSmallClass.hide(); $selThreeClass.hide(); $.getJSON("Scripts/CategoryJson.js", function (json) { var html = ['']; for (var key in json) { if (json[key].pid == 0) { html.push(''); } } //第一级类别 $selBigClass.empty().append(html.join('')).change(function () { $txtCategory.val(this.value); $selThreeClass.hide(); $selSmallClass.show(); var html = ['']; for (var data in json) { if (json[data].pid == $("#selBigClass").val()) { html.push(''); } } //第二级类别 $selSmallClass.empty().append(html.join('')).change(function () { $txtCategory.val(this.value); $selThreeClass.show(); var html = ['']; for (var data in json) { if (json[data].pid == $selSmallClass.val()) { html.push(''); } } //第三级类别 $selThreeClass.empty().append(html.join('')).change(function () { $txtCategory.val(this.value); }); //如果不存在第三级类别则隐藏第三级类别控件 if ($selThreeClass.get(0).options.length <= 1) { $selThreeClass.hide(); return false; } }); //如果不存在第二级类别则隐藏第二级类别控件 if ($selSmallClass.get(0).options.length <= 1) { $selSmallClass.hide(); return false; } }); }); };
Scripts/CategoryJson.js（如何生成json数据详见：http://www.cnblogs.com/haozhenjie819/p/3601676.html）
[{ "id": 31, "name": "\u65b0\u95fb\u4e2d\u5fc3", "pid": 0, "itemvalue": "|0|" },
{ "id": 59, "name": "\u52a0\u76df\u5408\u4f5c", "pid": 0, "itemvalue": "|0|" },
{ "id": 65, "name": "\u4ea7\u54c1\u670d\u52a1", "pid": 0, "itemvalue": "|0|" },
{ "id": 60, "name": "\u52a0\u76df\u987b\u77e5", "pid": 59, "itemvalue": "|0|59|" },
{ "id": 61, "name": "\u52a0\u76df\u6d41\u7a0b", "pid": 59, "itemvalue": "|0|59|" },
{ "id": 62, "name": "\u52a0\u76df\u533a\u57df", "pid": 59, "itemvalue": "|0|59|" },
{ "id": 70, "name": "\u63a8\u8350\u670d\u52a1", "pid": 65, "itemvalue": "|0|65|" },
{ "id": 71, "name": "\u8ba1\u8d39\u65b9\u5f0f", "pid": 65, "itemvalue": "|0|65|" },
{ "id": 72, "name": "\u7528\u6237\u987b\u77e5", "pid": 65, "itemvalue": "|0|65|" },
{ "id": 73, "name": "\u7981\u5bc4\u8303\u56f4", "pid": 65, "itemvalue": "|0|65|" },
{ "id": 75, "name": "\u666e\u901a\u5feb\u9012", "pid": 70, "itemvalue": "|0|65|70|" },
{ "id": 76, "name": "\u7279\u79cd\u5feb\u4ef6", "pid": 70, "itemvalue": "|0|65|70|" },
{ "id": 77, "name": "\u9650\u65f6\u6d3e\u9001", "pid": 70, "itemvalue": "|0|65|70|" },
{ "id": 78, "name": "\u4ee3\u6536\u8d37\u6b3e", "pid": 70, "itemvalue": "|0|65|70|" },
{ "id": 79, "name": "\u4fdd\u4ef7\u670d\u52a1", "pid": 70, "itemvalue": "|0|65|70|" },
{ "id": 80, "name": "\u4ee3\u7b7e\u56de\u5355", "pid": 70, "itemvalue": "|0|65|70|"}]
html页面
<html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>三级联动title> <script src="Scripts/jquery-1.4.1.min.js" type="text/javascript">script> <script src="Scripts/Category.js" type="text/javascript">script> head> <body> <form id="form1" runat="server"> <table> <tr> <td >新闻类别：td> <td > <input id="txtCategoryId" name="txtCategoryId" type="hidden" runat="server" />td> tr> table> form> body> html>
效果图
知识点：1、Jquery获取select中option个数
$("#selSmallClass").get(0).options.length