Jquery+Ajax+xml实现中国地区选择三级联动菜单效果(推荐)

<?xml version="1.0" encoding="utf-8"?><area Country="China"> <province ID="1" provinceID="110000" province="北京市">  <City CityID="110100" City="市辖区">   <Piecearea PieceareaID="110101" Piecearea="东城区" />   <Piecearea PieceareaID="110102" Piecearea="西城区" />   <Piecearea PieceareaID="110103" Piecearea="崇文区" />   <Piecearea PieceareaID="110104" Piecearea="宣武区" />   <Piecearea PieceareaID="110105" Piecearea="朝阳区" />   <Piecearea PieceareaID="110106" Piecearea="丰台区" />   <Piecearea PieceareaID="110107" Piecearea="石景山区" />   <Piecearea PieceareaID="110108" Piecearea="海淀区" />   <Piecearea PieceareaID="110109" Piecearea="门头沟区" />   <Piecearea PieceareaID="110111" Piecearea="房山区" />   <Piecearea PieceareaID="110112" Piecearea="通州区" />   <Piecearea PieceareaID="110113" Piecearea="顺义区" />   <Piecearea PieceareaID="110114" Piecearea="昌平区" />   <Piecearea PieceareaID="110115" Piecearea="大兴区" />   <Piecearea PieceareaID="110116" Piecearea="怀柔区" />   <Piecearea PieceareaID="110117" Piecearea="平谷区" />  </City><province>

<h2>地区三级联动菜单</h2>  省:<select id="province" onchange="showcity()"><option value="0">-请选择-</option></select>  市:<select id="city" onchange="showdistrict()"><option value="0">-请选择-</option></select>  地区:<select id="district"><option value="0">-请选择-</option></select>

//声明一个全局变量，用于存储第一次请求的xml信息,避免后续多次频繁请求xml    var xmldom =null;    //获取并显示省份信息    function showprovince(){      //使用ajax去服务器获得xml文件里面的省份信息      $.ajax({        url:'./ChinaArea.xml',        //data:        dataType:'xml',//相当于调用responseXML        type:'get',        success:function(msg){          //将返回的xml信息赋予xmldom          xmldom = msg;          //获得province 元素节点对象          var prov = $(msg).find('province');          //遍历省份信息          prov.each(function(k,v){            var nm = $(this).attr('province');            var id = $(this).attr('provinceID');            //追加到指定的节点            $('#province').append("<option value="+id+">"+nm+"</option>");          });        }      });    }    //网页加载显示省份信息      $(function(){      showprovince();    });    function showcity(){      //获取 省份 的id      var pid = $('#province option:selected').val();      //根据xmldom信息 找到指定的省份节点      var xml_province = $(xmldom).find('province[provinceID='+pid+']');      // 获取对应所有县市节点      var city = $(xml_province).find('City');      //在遍历追加前，先清空此前已经显示的信息      $('#city').empty();      $('#city').append('<option value="0">-请选择-</option>');      //遍历追加县市      city.each(function(k,v){        var nm = $(this).attr('City');        var id = $(this).attr('CityID');        $('#city').append('<option value='+id+'>'+nm+'</option>');      });    }    //以下函数的逻辑与showcity()的逻辑一致    function showdistrict(){      //获取 县市 的id      var cid = $('#city option:selected').val();      //根据xmldom信息 找到指定的县市节点      var xml_city = $(xmldom).find('City[CityID='+cid+']');      // 获取对应所有地区节点      var district = $(xml_city).find('Piecearea');      $('#district').empty();      $('#district').append('<option value="0">-请选择-</option>');      district.each(function(k,v){        var nm = $(this).attr('Piecearea');        var id = $(this).attr('PieceareaID');        $('#district').append('<option value='+id+'>'+nm+'</option>');      });    }