如何找出哪个DOM元素有焦点？ [英] How do I find out which DOM element has the focus?
问题描述
我想在Javascript中了解到哪个元素目前有焦点。我一直在看DOM，还没有找到我需要的东西。有没有办法做到这一点，怎么样？
I would like to find out, in Javascript, which element currently has focus. I've been looking through the DOM and haven't found what I need, yet. Is there a way to do this, and how?
我正在寻找的原因是：
我尝试使箭头和键进入导航一个输入元素表。标签现在工作，但输入，箭头不是默认情况下似乎。我已经设置了关键处理部分，但现在我需要弄清楚如何在事件处理函数中调整焦点。
I'm trying to make keys like the arrows and enter navigate through a table of input elements. Tab works now, but enter and arrows do not by default it seems. I've got the key handling part set up but now I need to figure out how to move the focus over in the event handling functions.
推荐答案
使用 document.activeElement ，所有主流浏览器都支持
Use document.activeElement, it is supported in all major browsers.
以前，如果你是试图找出什么样的字段有焦点，你不能。要在旧版浏览器中模拟检测，请在所有字段中添加一个focus事件处理程序，并将最后一个关注的字段记录在变量中。添加一个模糊处理程序来清除最后一个焦点字段的模糊事件的变量。
Previously, if you were trying to find out what form field has focus, you could not. To emulate detection within older browsers, add a "focus" event handler to all fields and record the last-focused field in a variable. Add a "blur" handler to clear the variable upon a blur event for the last-focused field.
相关链接：
- activeElement Browser Compatibility
- jQuery alternative for document.activeElement
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