static extern TODO DevicePowerState(TODO);

Declare Function DevicePowerState Lib "coredll.dll" (TODO) As TODO

   DevicePowerState DeviceState);

    Private Shared Function SetDevicePower(ByVal pvDevice As String, ByVal dwDeviceFlags As Integer, ByVal DeviceState As DevicePowerState) As Integer

public enum DevicePowerState : int

SetDevicePower("BKL1:", POWER_NAME, DevicePowerState.D4);

SetDevicePower("BKL1:", POWER_NAME, DevicePowerState.D0);

static extern bool GetDevicePowerState(IntPtr hDevice, out bool pfOn);

    bool result = GetDevicePowerState(hFile, out fOn);

    backlightHandle = NativeMethods.SetPowerRequirement("BKL1:", DevicePowerState.D0, 1, null, 0);

static extern int SetPowerRequirement(string DeviceName, DevicePowerState State, uint dwDeviceFlags, string Name, ulong Reserved);

Declare Function SetPowerRequirement Lib "coredll.dll" Alias "SetPowerRequirement" (ByVal DeviceName As String, ByVal state As DevicePowerState, ByVal dwDeviceFlags As UInteger, ByVal name As String, ByVal Reserved As ULong) As Integer

    public enum DevicePowerState : int

    Friend Enum DevicePowerState As Integer

          SetPowerRequirement("BKL1:",DevicePowerState.D0,POWER_NAME,null,0);