选择仅在一个<选项>上的onchange事件框 [英] Select box onchange event with only one <option>
本文介绍了选择仅在一个<选项>上的onchange事件框的处理方法,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
onchange事件运行良好并且填充我的输入(文本框)就好了,但是当onchange事件应用于下拉框时只有一个选项,它就不起作用了。即使有一个或多个项目,我如何才能获得onchange?
The onchange event works great and populates my input (textbox) just fine, but when the onchange event is applied to the drop down box with only 1 single option in it, it does not work. How can I get the onchange to fire even if, there is one or multiple items?
<!DOCTYPE html>
<html>
<head>
<style type="text/css">
</style>
<script type="text/javascript">
function test(x) {
var x = document.getElementById(x).options[document.getElementById(x).selectedIndex].text
document.getElementById('output').value = x
}//end of function
</script>
</head>
<body>
<select id="drop1" onchange="test(this.id)">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
<br><br>
<select id="drop2" onchange="test(this.id)">
<option value="volvo">Volvo</option>
</select>
<br><br>
<input type="text" id="output">
</body>
</html>
推荐答案
如果只有一个项目,它永远不会改变。请尝试 onblur
。或者 onclick
,具体取决于实际尝试做什么。
If there is only one item, it never will change. Try onblur
instead. Or maybe onclick
, depending on what you are actually trying to do.
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