Is there a way to detect whether the monitor is on/off?

  • Thread starter Thread starter Dikang Gu
  • Start date Start date
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Dikang Gu

that is, detect whether the user has turned on or off the monitor?

regards.
stephen
 
that is, detect whether the user has turned on or off the monitor?

regards.
stephen
Click to expand...

I guess it depend of the OS , in Vista you can detect if the speakers
are connected (very annoying feature of WMP btw).
You better check if WMI has any provision for that.
 
I guess it depend of the OS , in Vista you can detect if the speakers
are connected (very annoying feature of WMP btw).
You better check if WMI has any provision for that.
Click to expand...

How do you detect if the speakers are connected if the sound card
doesn't offer that information?

To the OP: Most video cards are capable of detecting whether a monitor
is _present_ or not, but as far as on or off, there really is no way
to deterministically find that out. At a hardware level, when a monitor
is connected there is resistance between 5 sets of pins on the display
adapter's pin array (for VGA). That only says whether a monitor is
*attached*, though.

This is how video cards can detect at boot time that they do not have a
monitor attached to them, but they don't freak out if a monitor is
attached but powered off.

The only deterministic method you can use (and it's outlandish) is to
require the user to have special hardware that can detect such a
situation, and you get notifications or be able to poll that hardware.

--- Mike
 
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