Keep the light on

[cyberco]

As discussed here:

http://groups.google.com/group/micr...578fa7db7c/de0dcfdfd113ab3b?#de0dcfdfd113ab3b

I am able to prevent my Windows Mobile device from going into suspend
mode, but the light goes off. Is there a way to keep the light on
indefinitely?

 

[Peter Foot [MVP]]

This should work:-
http://www.peterfoot.net/KeepYourSmartphoneBacklightOn.aspx

Peter

 

[cyberco]

Thanks, Peter, that seems to do what I'm after. Unfortunately I'm
completely new to VB and I'm not sure I'm translating the DLL imports
correctly to C#. Do you know if there is a C# example of this code
somewhere? I found this as well, but that doesn't talk about backlight
issues:
http://www.pcreview.co.uk/forums/thread-2299260.php

====== VB ==================================
Private Declare Function SetPowerRequirement Lib "coredll.dll" (ByVal
pvDevice As String, ByVal DeviceState As PowerState, ByVal DeviceFlags
As Integer, ByVal pvSystemState As IntPtr, ByVal StateFlags As Integer)
As IntPtr

Private Declare Function ReleasePowerRequirement Lib "coredll.dll"
(ByVal handle As IntPtr) As Integer
==================================

translated to C#

==== C# ==================================
[DllImport("coredll.dll", SetLastError = true)]
internal extern static int SetPowerRequirement(string pvDevice,
DevicePowerState deviceState, int deviceFlags, ref ??? systemState, int
StateFlags);

[DllImport("coredll.dll", SetLastError = true)]
internal extern static int ReleasePowerRequirement(???);
=========================================

The '???' mark where I got lost
Any suggestions?

 

[cyberco]

Thanks! I ended up with the following import statements:

==== C# ==================================
[DllImport("coredll.dll", SetLastError = true)]
internal extern static IntPtr SetPowerRequirement(string pvDevice,
DevicePowerState deviceState, int deviceFlags, IntPtr systemState, int
StateFlags);

[DllImport("coredll.dll", SetLastError = true)]
internal extern static int ReleasePowerRequirement(IntPtr handle);
=========================================

You can invoking this from within your C# code as follows:

==== C# ==================================
private static IntPtr handle;

public static void keepBackLightOn() {
handle = NativeMethods.SetPowerRequirement("BKL1:",
DevicePowerState.D0, 1, System.IntPtr.Zero,
}

public static void restoreBackLightSetting() {
if (handle.ToInt32() != 0) {
int result;
result = NativeMethods.ReleasePowerRequirement(handle);
handle = IntPtr.Zero;
}
}
=========================================