How can i turn on the screen backlight

Declare Sub SystemIdleTimerReset Lib "coredll" ()
Declare Sub SHIdleTimerReset Lib "Aygshell.dll" Alias "SHIdleTimerReset" ()

Const POWER_STATE_ON As Integer = &H10000
Const POWER_STATE_OFF As Integer = &H20000
Const POWER_STATE_SUSPEND As Integer = &H200000
Const POWER_FORCE As Integer = 4096
Declare Function SetSystemPowerState Lib "Coredll" ( _
ByVal pwrState As String, _
ByVal pwrStateFlags As Integer, _
ByVal Options As Integer) As Integer

Calling SetSystemPowerState will turn the backlight on.

If KeepAlive = True Then
SetSystemPowerState(Nothing, POWER_STATE_ON, POWER_FORCE)
SystemIdleTimerReset()
SHIdleTimerReset()
End If

crt at 2007-9-4 >

The MSDN how-to article in my initial answer shows how to do this (here).

To restore the default behavoir:
call the native API ReleasePowerRequirement. (Pass in the handle returned by the previous call to SetPowerRequirement)

To turn the backlight back on: call the native API SetPowerRequirement as shown in the above sample.

MichaelKoster at 2007-9-4 >