javascript 如何检测JS中的焦点更改事件？
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How to detect focus changed event in JS?
提问by CharlesX
I want to write a function, this function can detect whether the focus is on the certain element.If the focus is on the element, I call the onfocus()function, and if not on the element, I do nothing.How can I do this?
我想写一个函数，这个函数可以检测焦点是否在某个元素上。如果焦点在该元素上，我调用该onfocus()函数，如果不在该元素上，我什么都不做。我该怎么做？
回答by imbondbaby
Many different ways to do this.
许多不同的方法来做到这一点。
Here is 2 examples:
这里有2个例子：
Solution #1:
解决方案#1：
You could use simple inline onblurfunction to see if that certain element is focused out. This is probably the simplest way to do it.
您可以使用简单的内联onblur函数来查看某个元素是否被突出显示。这可能是最简单的方法。
<input type="text" onblur="javascript:alert('You have focused out');" />
Solution #2:
解决方案#2：
HTML:
HTML：
<input type="text" />
JQuery:
查询：
var selectedInput = null;
$(function() {
$('input').focus(function() {
selectedInput = this;
}).blur(function(){
selectedInput = null;
alert("You have focused out");
});
});
If you want multiple, you could use:
如果你想要多个，你可以使用：
$('input, textarea, select').focus(function() {
You could use blurand focusfunctions to see if that certain element is focused.
您可以使用blur和focus函数来查看某个元素是否被聚焦。
