jQuery: How can I tell when a tab/window gains focus

问题

Is there an event that I can register for that fires each time the user clicks on a tab, meaning that they were on my page's tab, clicked on another tab, then came back to my tab.

EDIT: By tabs, I mean browser tabs, not jQueryUI tabs.

回答1:

Matijis provided this answer in a comment, but I wanted to accept it so here it is as an answer.

$(window).on('focus', function() { // your code });

回答2:

Try using jquery $(selector).focusin or :focus, they both work quite the same way.

http://api.jquery.com/focusin/

http://api.jquery.com/focus-selector/

来源：https://stackoverflow.com/questions/9365576/jquery-how-can-i-tell-when-a-tab-window-gains-focus