当前位置:Gxlcms > JavaScript > js 触发select onchange事件代码

js 触发select onchange事件代码

时间:2021-07-01 10:21:17 帮助过:5人阅读

select 或text的onchange事件需要手动(通过键盘输入)改变select或text的值才能触发,如果在js中给select或text赋值,则无法触发onchang事件,
例如,在页面加载完成以后,需要触发一个onChange事件,在js中用document.getElementById("province").value="湖北";直接给select或text赋值是不行的,要想实现手动触发onchange事件,需要在js给select赋值后,加入下面的语句

document.getElementById("province").fireEvent('onchange') 来实现,
代码如下:

<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script type="text/javascript">
var provinces = new Array();
provinces["湖北"] = ["武汉","襄阳","随州","宜昌","十堰"];
provinces["四川"] = ["成都","内江","达州"];
provinces["河南"] =["郑州","南阳","信阳","漯河"];
function changeProvince()
{
var prov = document.getElementById("province").value;
var city =document.getElementById("city");
city.options.length =0;
for(var i in provinces[prov])
{
city.options.add(new Option(provinces[prov][i],provinces[prov][i]));
}
}
window.onload = function(){
var province = document.getElementById("province");

for(var index in provinces)
{
//alert(index);
province.options.add(new Option(index,index));
}
province.fireEvent("onchange");
};
</script>
</head>
<body>
省份:<select id="province" onchange= "changeProvince()"></select>
城市:<select id="city"></select>
</body>
</html>

人气教程排行