javascript - 我如何找出哪个DOM元素具有焦点？(How do I find out which DOM element has the focus?)

Question

I would like to find out, in JavaScript, which element currently has focus.(我想用JavaScript找出当前关注的元素。)

I've been looking through the DOM and haven't found what I need, yet.(我一直在浏览DOM，但尚未找到我需要的东西。) Is there a way to do this, and how?(有办法做到这一点吗？) The reason I was looking for this:(我寻找这个的原因：) I'm trying to make keys like the arrows and enter navigate through a table of input elements.(我试图使像箭头键和enter通过输入元素表中导航。) Tab works now, but enter, and arrows do not by default it seems.(选项卡现在可以使用，但是可以输入，默认情况下，箭头没有显示。) 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.(我已经设置了关键处理部分，但是现在我需要弄清楚如何在事件处理功能中转移焦点。)   ask by Tony Peterson translate from so

Answer 1

Use document.activeElement , it is supported in all major browsers.(使用document.activeElement ，所有主要浏览器都支持它。)

Previously, if you were trying to find out what form field has focus, you could not.(以前，如果您试图找出哪个表单字段具有焦点，则无法。) To emulate detection within older browsers, add a "focus" event handler to all fields and record the last-focused field in a variable.(要在较旧的浏览器中模拟检测，请向所有字段添加“焦点”事件处理程序，并将最后关注的字段记录在变量中。) Add a "blur" handler to clear the variable upon a blur event for the last-focused field.(添加一个“模糊”处理程序，以在发生模糊事件时清除最后关注的字段的变量。) Related links:(相关链接：) activeElement Browser Compatibility(activeElement浏览器兼容性) jQuery alternative for document.activeElement(jQuery document.activeElement的替代方案)