js实现 多级联动

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta charset="utf-8">
<title>dispatchEvent示例用法</title>
<script type="text/javascript">
var provinces = new Array();
provinces["陕西"] = ["西安","咸阳","宝鸡","延安","汉中"];
provinces["台湾"] = ["台北","台中","台南"];
provinces["浙江"] = ["杭州","宁波","绍兴","温州"];
console.log(provinces);

function provinceChange()
{   
    console.log("onChange is triggered.");
    var prov = document.getElementById("province").value;
    var cityObj = document.getElementById("city");
    cityObj.options.length =0;
    for(var i in provinces[prov])
    {
        cityObj.options.add(new Option(provinces[prov][i],provinces[prov][i]));
    }
}
window.onload = function(){
    var provinceObj = document.getElementById("province");
    for(var index in provinces)
    {
        provinceObj.options.add(new Option(index,index));
    }

    var event = document.createEvent('HTMLEvents');
    event.initEvent("change", true, true);
    event.eventType = 'message';
    provinceObj.dispatchEvent(event);
};
</script>
</head>
<body>
省份:<select id="province" onchange= "provinceChange()"></select>
城市:<select id="city"></select>
</body>
</html>

 

posted @ 2018-11-28 10:25  二月花开  阅读(2358)  评论(0编辑  收藏  举报