从下拉菜单中激活或选中带有onchange事件的复选框 [英] Activate or check checkbox with onchange event from dropdown
本文介绍了从下拉菜单中激活或选中带有onchange事件的复选框的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
JavaScript和我永远都不是最好的朋友.
Javascript and I will never be best friends.
我尝试通过更改下拉列表中的元素来设置要选中的复选框.
I try to set a checkbox to checked by changing the elements from a dropdownlist.
这是代码段
<select name="change_status_to" id="sel">
<option>....</option>
<option>....</option>
</select>
<input type="checkbox" name="do_status_change" value="on">
如何将Javascript与onchange-event结合使用,以将复选框设置为选中状态?
How could I use Javascript with the onchange-event to set the checkbox to the state checked?
推荐答案
以下是您应该与javascript成为朋友的一个示例.
Here is an example of why you should be friends with javascript.
JSFiddle- http://jsfiddle.net/juc7Q/1/
JSFiddle - http://jsfiddle.net/juc7Q/1/
HTML
You're feeling toward Javascript
<select name="friends" id="friends">
<option value="love">I love JS</option>
<option value="weird">JS is weird</option>
<option value="misunderstood">Are we speaking the same language?</option>
</select>
<button id="selectWeird">Keep JS Weird</button>
<div>
<input type="checkbox" id="we_friends"> - Friends?
</div>
JavaScript
//Select this using js
var list = document.getElementById('friends');
var cb = document.getElementById('we_friends');
//Add event when change happens
list.onchange = function () {
var value = list.value;
if(value == 'love') {
alert('I knew you would come around');
cb.setAttribute('checked', '');
} else if(value == 'weird') {
alert('And I like being weird :-)!!');
cb.removeAttribute('checked');
} else {
alert('And you think I understand you?');
cb.removeAttribute('checked');
}
}
//Change to 'Weird' when I click on it
var btn = document.getElementById('selectWeird');
btn.onclick = function () {
list.options.selectedIndex = 1;
}
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