您如何使用javascript检测用户是否有多台显示器？

Question

Is it possible to use javascript to detect if a user has multiple monitors? And additionally if the monitors are "cloned" or in "extended desktop" mode?

Answer 1

I'm pretty sure it's impossible to find that out but you can make an educated guess using the following (untested) code:

var dual_monitor = ( (screen.width / screen.height) > 2 )

This will test if the (total) monitor width is at least twice as wide as the height, the closest (normal) ratio is 16:9, even this would return false, so If dual_monitor == true , it is fairly safe to say that the user has two monitors.

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PS This will only cover situations where the use has side-by-side, non-cloned displays.