C# Signature:
enum POWER_ACTION : uint
{
PowerActionNone = 0, // No system power action.
PowerActionReserved, // Reserved; do not use.
PowerActionSleep, // Sleep.
PowerActionHibernate, // Hibernate.
PowerActionShutdown, // Shutdown.
PowerActionShutdownReset, // Shutdown and reset.
PowerActionShutdownOff, // Shutdown and power off.
PowerActionWarmEject, // Warm eject.
}
[Flags]
enum PowerActionFlags : uint
{
POWER_ACTION_QUERY_ALLOWED = 0x00000001, // Broadcasts a PBT_APMQUERYSUSPEND event to each application to request permission to suspend operation.
POWER_ACTION_UI_ALLOWED = 0x00000002, // Applications can prompt the user for directions on how to prepare for suspension. Sets bit 0 in the Flags parameter passed in the lParam parameter of
WM_POWERBROADCAST.
POWER_ACTION_OVERRIDE_APPS = 0x00000004, // Ignores applications that do not respond to the PBT_APMQUERYSUSPEND event broadcast in the WM_POWERBROADCAST message.
POWER_ACTION_LIGHTEST_FIRST = 0x10000000, // Uses the first lightest available sleep state.
POWER_ACTION_LOCK_CONSOLE = 0x20000000, // Requires entry of the system password upon resume from one of the system standby states.
POWER_ACTION_DISABLE_WAKES = 0x40000000, // Disables all wake events.
POWER_ACTION_CRITICAL = 0x80000000, // Forces a critical suspension.
}
[Flags]
enum PowerActionEventCode : uint
{
POWER_LEVEL_USER_NOTIFY_TEXT = 0x00000001, // User notified using the UI.
POWER_LEVEL_USER_NOTIFY_SOUND = 0x00000002, // User notified using sound.
POWER_LEVEL_USER_NOTIFY_EXEC = 0x00000004, // Specifies a program to be executed.
POWER_USER_NOTIFY_BUTTON = 0x00000008, // Indicates that the power action is in response to a user power button press.
POWER_USER_NOTIFY_SHUTDOWN = 0x00000010, // Indicates a power action of shutdown/off.
POWER_FORCE_TRIGGER_RESET = 0x80000000, // Clears a user power button press.
}
enum SYSTEM_POWER_STATE : UInt32
{
PowerSystemUnspecified = 0,
PowerSystemWorking = 1,
PowerSystemSleeping1 = 2,
PowerSystemSleeping2 = 3,
PowerSystemSleeping3 = 4,
PowerSystemHibernate = 5,
PowerSystemShutdown = 6,
PowerSystemMaximum = 7
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
struct POWER_ACTION_POLICY
{
public POWER_ACTION Action;
public PowerActionFlags Flags;
public PowerActionEventCode EventCode;
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
struct SYSTEM_POWER_LEVEL // SIZE MUST BE 24 bytes
{
public byte Enable;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
public byte[] Spare;
public uint BatteryLevel;
public POWER_ACTION_POLICY PowerPolicy;
public SYSTEM_POWER_STATE MinSystemState;
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
struct SYSTEM_POWER_POLICY // SIZE MUST BE 232 bytes
{
public UInt32 Revision;
public POWER_ACTION_POLICY PowerButton;
public POWER_ACTION_POLICY SleepButton;
public POWER_ACTION_POLICY LidClose;
public SYSTEM_POWER_STATE LidOpenWake;
public UInt32 Reserved;
public POWER_ACTION_POLICY Idle;
public UInt32 IdleTimeout;
public byte IdleSensitivity;
public byte DynamicThrottle;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
public byte[] Spare2;
public SYSTEM_POWER_STATE MinSleep;
public SYSTEM_POWER_STATE MaxSleep;
public SYSTEM_POWER_STATE ReducedLatencySleep;
public UInt32 WinLogonFlags;
public UInt32 Spare3;
public UInt32 DozeS4Timeout;
public UInt32 BroadcastCapacityResolution;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
public SYSTEM_POWER_LEVEL[] DischargePolicy;
public UInt32 VideoTimeout;
public byte VideoDimDisplay;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
public UInt32[] VideoReserved;
public UInt32 SpindownTimeout;
public byte OptimizeForPower;
public byte FanThrottleTolerance;
public byte ForcedThrottle;
public byte MinThrottle;
public POWER_ACTION_POLICY OverThrottled;
}
VB Signature:
Declare Function SYSTEM_POWER_POLICY Lib "powrprof.dll" (TODO) As TODO
User-Defined Types:
None.
Alternative Managed API:
Do you know one? Please contribute it!
Notes:
Please make sure that the size of SYSTEM_POWER_LEVEL is 24 bytes (Marshal.SizeOf(typeof(SYSTEM_POWER_LEVEL))) and the size of SYSTEM_POWER_POLICY (Marshal.SizeOf(typeof(SYSTEM_POWER_POLICY))) is 232 bytes. If the size is off, CallNtPowerInformation will return STATUS_INVALID_PARAMETER (0xC000000D).
Tips & Tricks:
Please add some!
Sample Code:
class changePowerSettings
{
const uint STATUS_SUCCESS = 0;
/// <summary>
/// Indicates the specific power information to be set or retrieved. It used as a parameter in CallNtPowerInformation function.
/// </summary>
public enum POWER_INFORMATION_LEVEL : Int32
{
/// <summary>
/// <para> The lpInBuffer parameter must be NULL; otherwise, the function returns ERROR_INVALID_PARAMETER.</para>
///The lpOutputBuffer buffer receives a ULONGLONG that specifies the interrupt-time count, in 100-nanosecond units, at the last system sleep time.
/// </summary>
LastSleepTime = 15,
/// <summary>
/// <para> The lpInBuffer parameter must be NULL; otherwise, the function returns ERROR_INVALID_PARAMETER.</para>
/// The lpOutputBuffer buffer receives a ULONGLONG that specifies the interrupt-time count, in 100-nanosecond units, at the last system wake time.
/// </summary>
LastWakeTime = 14,
/// <summary>
/// <para> The lpInBuffer parameter must be NULL; otherwise the function returns ERROR_INVALID_PARAMETER.</para>
/// The lpOutputBuffer buffer receives one PROCESSOR_POWER_INFORMATION structure for each processor that is installed on the system. Use the GetSystemInfo function to retrieve the number of processors.
/// </summary>
ProcessorInformation = 11,
/// <summary>
/// <para> The lpInBuffer parameter must be NULL; otherwise, the function returns ERROR_INVALID_PARAMETER.</para>
/// The lpOutputBuffer buffer receives a SYSTEM_BATTERY_STATE structure containing information about the current system battery.
/// </summary>
SystemBatteryState = 5,
/// <summary>
/// <para> The lpInBuffer parameter must be NULL; otherwise the function returns ERROR_INVALID_PARAMETER.</para>
/// The lpOutputBuffer buffer receives a ULONG value containing the system execution state buffer.
/// <para> This value may contain any combination of the following values: ES_SYSTEM_REQUIRED, ES_DISPLAY_REQUIRED, or ES_USER_PRESENT.</para>
/// For more information, see the SetThreadExecutionState function.
/// </summary>
SystemExecutionState = 16,
/// <summary>
/// <para> The lpInBuffer parameter must be NULL, otherwise, the function returns ERROR_INVALID_PARAMETER.</para>
/// The lpOutputBuffer buffer receives a SYSTEM_POWER_CAPABILITIES structure containing the current system power capabilities.
/// <para> This information represents the currently supported power capabilities. It may change as drivers are installed in the system.
/// For example, installation of legacy device drivers that do not support power management disables all system sleep states.</para>
/// </summary>
SystemPowerCapabilities = 4,
/// <summary>
/// <para> The lpInBuffer parameter must be NULL; otherwise, the function returns ERROR_INVALID_PARAMETER.</para>
/// The lpOutputBuffer buffer receives a SYSTEM_POWER_INFORMATION structure.
/// <para> Applications can use this level to retrieve information about the idleness of the system.</para>
/// </summary>
SystemPowerInformation = 12,
/// <summary>
/// <para> If lpInBuffer is not NULL, the function applies the SYSTEM_POWER_POLICY values passed in lpInBuffer to the current system power policy used while the system is running on AC (utility) power.</para>
/// The lpOutputBuffer buffer receives a SYSTEM_POWER_POLICY structure containing the current system power policy used while the system is running on AC (utility) power.
/// </summary>
SystemPowerPolicyAc = 0,
/// <summary>
/// <para> The lpInBuffer parameter must be NULL; otherwise, the function returns ERROR_INVALID_PARAMETER.</para>
/// The lpOutputBuffer buffer receives a SYSTEM_POWER_POLICY structure containing the current system power policy used while the system is running on AC (utility) power.
/// </summary>
SystemPowerPolicyCurrent = 8,
/// <summary>
/// <para> If lpInBuffer is not NULL, the function applies the SYSTEM_POWER_POLICY values passed in lpInBuffer to the current system power policy used while the system is running on battery power.</para>
/// The lpOutputBuffer buffer receives a SYSTEM_POWER_POLICY structure containing the current system power policy used while the system is running on battery power.
/// </summary>
SystemPowerPolicyDc = 1,
/// <summary>
/// <para> If lpInBuffer is not NULL and the current user has sufficient privileges, the function commits or decommits the storage required to hold the hibernation image on the boot volume.</para>
/// The lpInBuffer parameter must point to a BOOLEAN value indicating the desired request. If the value is TRUE, the hibernation file is reserved; if the value is FALSE, the hibernation file is removed.
/// </summary>
SystemReserveHiberFile = 10
}
enum POWER_ACTION : uint
{
PowerActionNone = 0, // No system power action.
PowerActionReserved, // Reserved; do not use.
PowerActionSleep, // Sleep.
PowerActionHibernate, // Hibernate.
PowerActionShutdown, // Shutdown.
PowerActionShutdownReset, // Shutdown and reset.
PowerActionShutdownOff, // Shutdown and power off.
PowerActionWarmEject, // Warm eject.
}
[Flags]
enum PowerActionFlags : uint
{
POWER_ACTION_QUERY_ALLOWED = 0x00000001, // Broadcasts a PBT_APMQUERYSUSPEND event to each application to request permission to suspend operation.
POWER_ACTION_UI_ALLOWED = 0x00000002, // Applications can prompt the user for directions on how to prepare for suspension. Sets bit 0 in the Flags parameter passed in the lParam parameter of WM_POWERBROADCAST.
POWER_ACTION_OVERRIDE_APPS = 0x00000004, // Ignores applications that do not respond to the PBT_APMQUERYSUSPEND event broadcast in the WM_POWERBROADCAST message.
POWER_ACTION_LIGHTEST_FIRST = 0x10000000, // Uses the first lightest available sleep state.
POWER_ACTION_LOCK_CONSOLE = 0x20000000, // Requires entry of the system password upon resume from one of the system standby states.
POWER_ACTION_DISABLE_WAKES = 0x40000000, // Disables all wake events.
POWER_ACTION_CRITICAL = 0x80000000, // Forces a critical suspension.
}
[Flags]
enum PowerActionEventCode : uint
{
POWER_LEVEL_USER_NOTIFY_TEXT = 0x00000001, // User notified using the UI.
POWER_LEVEL_USER_NOTIFY_SOUND = 0x00000002, // User notified using sound.
POWER_LEVEL_USER_NOTIFY_EXEC = 0x00000004, // Specifies a program to be executed.
POWER_USER_NOTIFY_BUTTON = 0x00000008, // Indicates that the power action is in response to a user power button press.
POWER_USER_NOTIFY_SHUTDOWN = 0x00000010, // Indicates a power action of shutdown/off.
POWER_FORCE_TRIGGER_RESET = 0x80000000, // Clears a user power button press.
}
enum SYSTEM_POWER_STATE : UInt32
{
PowerSystemUnspecified = 0,
PowerSystemWorking = 1,
PowerSystemSleeping1 = 2,
PowerSystemSleeping2 = 3,
PowerSystemSleeping3 = 4,
PowerSystemHibernate = 5,
PowerSystemShutdown = 6,
PowerSystemMaximum = 7
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
struct POWER_ACTION_POLICY
{
public POWER_ACTION Action;
public PowerActionFlags Flags;
public PowerActionEventCode EventCode;
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
struct SYSTEM_POWER_LEVEL // SIZE MUST BE 24 bytes
{
public byte Enable;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
public byte[] Spare;
public uint BatteryLevel;
public POWER_ACTION_POLICY PowerPolicy;
public SYSTEM_POWER_STATE MinSystemState;
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
struct SYSTEM_POWER_POLICY // SIZE MUST BE 232 bytes
{
public UInt32 Revision;
public POWER_ACTION_POLICY PowerButton;
public POWER_ACTION_POLICY SleepButton;
public POWER_ACTION_POLICY LidClose;
public SYSTEM_POWER_STATE LidOpenWake;
public UInt32 Reserved;
public POWER_ACTION_POLICY Idle;
public UInt32 IdleTimeout;
public byte IdleSensitivity;
public byte DynamicThrottle;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
public byte[] Spare2;
public SYSTEM_POWER_STATE MinSleep;
public SYSTEM_POWER_STATE MaxSleep;
public SYSTEM_POWER_STATE ReducedLatencySleep;
public UInt32 WinLogonFlags;
public UInt32 Spare3;
public UInt32 DozeS4Timeout;
public UInt32 BroadcastCapacityResolution;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
public SYSTEM_POWER_LEVEL[] DischargePolicy;
public UInt32 VideoTimeout;
public byte VideoDimDisplay;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
public UInt32[] VideoReserved;
public UInt32 SpindownTimeout;
public byte OptimizeForPower;
public byte FanThrottleTolerance;
public byte ForcedThrottle;
public byte MinThrottle;
public POWER_ACTION_POLICY OverThrottled;
}
[DllImport("powrprof.dll")]
static extern uint CallNtPowerInformation(
int InformationLevel,
[In] SYSTEM_POWER_POLICY[] lpInputBuffer,
int nInputBufferSize,
[Out] SYSTEM_POWER_POLICY[] lpOutputBuffer,
int nOutputBufferSize
);
public changePowerSettings()
{
SYSTEM_POWER_POLICY[] powerInfo = new SYSTEM_POWER_POLICY[1];
int splSize = Marshal.SizeOf(typeof(SYSTEM_POWER_LEVEL));
int structureSize = Marshal.SizeOf(typeof(SYSTEM_POWER_POLICY));
uint retval = CallNtPowerInformation(
(int)POWER_INFORMATION_LEVEL.SystemPowerPolicyAc,
null,
0,
powerInfo,
structureSize
);
if (retval == STATUS_SUCCESS)
{
// do something
}
}
}
