JavaScript实现省市区的三级联动

JavaScript实现省市区的三级联动

 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Insert title here</title>
 </head>
 <body>
 <div id="div1">
 </div>
 <script type="text/javascript">
     /* 创建省 */
     var provinceAr = ["湖北省","吉林省","湖南省"];
     var province = document.createElement("select");
     var province_one = document.createElement("option");
     var province_one_value = document.createTextNode("请选择省");
     province_one.appendChild(province_one_value);
     province.appendChild(province_one);
     document.getElementById("div1").appendChild(province);
     for(var i = 0; i < provinceAr.length; i++){
         province_one = document.createElement("option");
         province_one_value = document.createTextNode(provinceAr[i]);
         province_one.appendChild(province_one_value);
         province.appendChild(province_one);
     }
     /* 创建市 */
     var cityAr = [
                   ["襄阳市","武汉市","荆门市","恩施市"],
                   ["长春市","四平市","松原市"],
                   ["长沙市","岳阳市","益阳市"],
                   ];
     province.id = "proi";//给省添加id
     var city = document.createElement("select");
     document.getElementById("div1").appendChild(city);
     var city_one = document.createElement("option");
     var city_one_value = document.createTextNode("请选择市");
     city_one.appendChild(city_one_value);
     city.appendChild(city_one);
     city.id="cityI";//给市添加id
     /* 创建县 */
     var townAr = [
                 [
                      ["樊城区","襄州区","襄城区"],
                      ["江汉区","汉阳区","武昌区"],
                      ["京沙县","沙洋县","东宝区"],
                      ["舞阳坝街道","小渡船街道","六角亭街道"]
                  ],
                 [
                      ["南关区 ","朝阳区","宽城区"],
                      ["铁东区","铁西区","梨树县"],
                      ["宁江区","乾安县","长岭县"]
                  ],
                 [
                      ["长沙县 ","宁乡县","浏阳市"],
                      ["湘阴县","岳阳县","华容县"],
                      ["安化","桃江","南县"]
                  ]
                 ];
     var town = document.createElement("select");
     var town_one = document.createElement("option");
     var town_one_value = document.createTextNode("请选择县");
     town_one.appendChild(town_one_value);
     town.appendChild(town_one);
     document.getElementById("div1").appendChild(town);
     /* onchange拼写出错可能导致进程终止*/
     province.onchange = function(){
         var index = document.getElementById("proi").selectedIndex;//给select一个索引值
         city.innerHTML="";
         if(index==0){
             var city_one = document.createElement("option");
             var city_one_value = document.createTextNode("请选择市");
             city_one.appendChild(city_one_value);
             city.appendChild(city_one);
             town.innerHTML="";
             var town_one = document.createElement("option");
             var town_one_value = document.createTextNode("请选择县");
             town_one.appendChild(town_one_value);
             town.appendChild(town_one);
         }
         else
         {
             var cityValues = cityAr[index-1];
             var townValu = townAr[index-1];//townValu为一个二维数组
             console.log(cityValues);
             console.log(townValu);
             for(var i = 0; i < cityValues.length; i++){
                 var city_one = document.createElement("option");
                 var city_one_value = document.createTextNode(cityValues[i]);
                 city_one.appendChild(city_one_value);
                 city.appendChild(city_one);
             }
             var tor = townValu[0];
             console.log(tor);
             town.innerHTML="";
             for(var i = 0; i < tor.length; i++)
             {
             var town_one = document.createElement("option");
             var town_one_value = document.createTextNode(tor[i]);
             town_one.appendChild(town_one_value);
             town.appendChild(town_one);
             }
             city.onchange=function(){
                 var indexc = document.getElementById("cityI").selectedIndex;
                 var townVa = townValu[indexc];
                 town.innerHTML="";
                 console.log(townVa);
                 for(var i = 0; i < townVa.length; i++)
                 {
                 var town_one = document.createElement("option");
                 var town_one_value = document.createTextNode(townVa[i]);
                 town_one.appendChild(town_one_value);
                 town.appendChild(town_one);
                 }
             }
         }
     }
 </script>
 </body>
 </html>

调试

备注

1. .innerHTML=" "的作用是为了清空select下的option样式，若不清空可能会导致select索引值发生改变

参考链接

http://www.w3school.com.cn/xmldom/met_document_createelement.asp（createElement() 方法）

http://www.w3school.com.cn/jsref/prop_option_index.asp（HTML DOM index属性）