javascript:窗口外的事件

Question

是否可以获取在浏览器窗口之外触发的鼠标事件？或者当鼠标移动到窗口上时是否可以检查鼠标是否被按下？

Answer 1

这是不可能的，但是从这句话来看 -

Or is it possible to check if the mouse is pressed when the mouse is moved over a window

您可以检查页面何时获得焦点，以及何时有人切换回您的页面选项卡。

window.onfocus = function() {
   console.log('focus');
   alert('focus'); // See note
};

Note - If you use alert in the onfocus event the alert will popup multiple times. This only happens with alert and must be a bug somewhere, maybe someone can shed some light on it.

Demo