js 觸發select onchange事件代碼

2024-05-06 16:03:03

字體：大中小

來源：轉載

供稿：網友

select 或text的onchange事件需要手動（通過鍵盤輸入）改變select或text的值才能觸發，本文為大家介紹下使用js觸發select onchange事件

select 或text的onchange事件需要手動（通過鍵盤輸入）改變select或text的值才能觸發，如果在js中給select或text賦值，則無法觸發onchang事件，
例如，在頁面加載完成以后，需要觸發一個onChange事件，在js中用document.getElementById("province").value="湖北";直接給select或text賦值是不行的，要想實現手動觸發onchange事件，需要在js給select賦值后，加入下面的語句

document.getElementById("province").fireEvent('onchange') 來實現,

復制代碼代碼如下:

<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>無標題文檔</title>
<script type="text/javascript">
var provinces = new Array();
provinces["湖北"] = ["武漢","襄陽","隨州","宜昌","十堰"];
provinces["四川"] = ["成都","內江","達州"];
provinces["河南"] =["鄭州","南陽","信陽","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 onchange= "changeProvince()"></select>
城市:<select></select>
</body>
</html>