使用纯 JavaScript 获取事件的选择元素值
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Get select element value on event using pure JavaScript
提问by AlexMorley-Finch
I want to get the value of a select element when the select element is clicked! I want to do it without an onchangeattribute in the HTML.
我想在单击选择元素时获取选择元素的值！我想onchange在 HTML 中没有属性的情况下做到这一点。
I would like to achieve this without jQuery. I don't want to include a jQuery framework into this website when this tiny script is the only thing I need.
我想在没有 jQuery 的情况下实现这一点。当这个小脚本是我唯一需要的东西时，我不想在这个网站中包含一个 jQuery 框架。
var select_element = document.getElementById('product-form-user-enquiry-type');
select_element.onchange = function(e){
if (!e)
var e = window.event;
var svalue = select_element.value;
alert( svalue );
}
if ( select_element.captureEvents ){
select_element.captureEvents(Event.CHANGE);
}
The select_element.value;contains an empty string. How should I do this?
该select_element.value;包含一个空字符串。我该怎么做？
采纳答案by AymKdn
A solution that will work with all browsers (including IE8) :
适用于所有浏览器（包括 IE8）的解决方案：
var select_element = document.getElementById('product-form-user-enquiry-type');
select_element.onchange = function() {
var elem = (typeof this.selectedIndex === "undefined" ? window.event.srcElement : this);
var value = elem.value || elem.options[elem.selectedIndex].value;
alert(value);
}?
回答by Gavin
?document.getElementById('test').onchange = function() {
alert(this.options[this.selectedIndex].val???ue);
};?
Does the above the work?
以上有效吗？
Edit:
编辑：
Edited to reflect your select id's etc.
编辑以反映您选择的 ID 等。
var select_element = document.getElementById('product-form-user-enquiry-type');
select_element.onchange = function(e){
if (!e)
var e = window.event;
var svalue = this.options[this.selectedIndex].value;
alert( svalue );
}?
See it working at: http://jsfiddle.net/gRoberts/4WUsG/
看到它的工作：http: //jsfiddle.net/gRoberts/4WUsG/
回答by vladkras
.onchange = function() { ... }seems to overwrite other handlers, so I use addEventListener("change", function() { ... })
.onchange = function() { ... }似乎覆盖其他处理程序，所以我使用addEventListener("change", function() { ... })
