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PowerEnumerate function

Applies to: desktop apps only

Enumerates the specified elements in a power scheme. This function is normally called in a loop incrementing the Index parameter to retrieve subkeys until they've all been enumerated.

Syntax

Copy

DWORD WINAPI PowerEnumerate(
  __in_opt   HKEY RootPowerKey,
  __in_opt   const GUID *SchemeGuid,
  __in_opt   const GUID *SubGroupOfPowerSettingsGuid,
  __in       POWER_DATA_ACCESSOR AccessFlags,
  __in       ULONG Index,
  __out_opt  UCHAR *Buffer,
  __inout    DWORD *BufferSize
);

Parameters

RootPowerKey [in, optional]

This parameter is reserved for future use and must be set to NULL.

SchemeGuid [in, optional]

The identifier of the power scheme. If this parameter is NULL, an enumeration of the power policies is returned.

SubGroupOfPowerSettingsGuid [in, optional]

The subgroup of power settings. If this parameter is NULL, an enumeration of settings under the PolicyGuid key is returned.

Value	Meaning
NO_SUBGROUP_GUID fea3413e-7e05-4911-9a71-700331f1c294	Settings in this subgroup will be part of the default power scheme.
GUID_DISK_SUBGROUP 0012ee47-9041-4b5d-9b77-535fba8b1442	Settings in this subgroup control power management configuration of the system's hard disk drives.
GUID_SYSTEM_BUTTON_SUBGROUP 4f971e89-eebd-4455-a8de-9e59040e7347	Settings in this subgroup control configuration of the system power buttons.
GUID_PROCESSOR_SETTINGS_SUBGROUP 54533251-82be-4824-96c1-47b60b740d00	Settings in this subgroup control configuration of processor power management features.
GUID_VIDEO_SUBGROUP 7516b95f-f776-4464-8c53-06167f40cc99	Settings in this subgroup control configuration of the video power management features.
GUID_BATTERY_SUBGROUP e73a048d-bf27-4f12-9731-8b2076e8891f	Settings in this subgroup control battery alarm trip points and actions.
GUID_SLEEP_SUBGROUP 238C9FA8-0AAD-41ED-83F4-97BE242C8F20	Settings in this subgroup control system sleep settings.
GUID_PCIEXPRESS_SETTINGS_SUBGROUP 501a4d13-42af-4429-9fd1-a8218c268e20	Settings in this subgroup control PCI Express settings.

AccessFlags [in]

A set of flags that specifies what will be enumerated

Value	Meaning
ACCESS_SCHEME 16	Enumerate power schemes. The SchemeGuid and SubgroupOfPowerSettingsGuid parameters will be ignored.
ACCESS_SUBGROUP 17	Enumerate subgroups under SchemeGuid. The SubgroupOfPowerSettingsGuid parameter will be ignored.
ACCESS_INDIVIDUAL_SETTING 18	Enumerate individual power settings under SchemeGuid\SubgroupOfPowerSettingsGuid. To enumerate power settings directly under the SchemeGuid key, use NO_SUBGROUP_GUID as the SubgroupOfPowerSettingsGuid parameter.

Index [in]

The zero-based index of the scheme, subgroup, or setting that is being enumerated.

Buffer [out, optional]

A pointer to a variable to receive the elements. If this parameter is NULL, the function retrieves the size of the buffer required.

BufferSize [in, out]

A pointer to a variable that on input contains the size of the buffer pointed to by the Buffer parameter. If the Buffer parameter is NULL or if the BufferSize is not large enough, the function will return ERROR_MORE_DATA and the variable receives the required buffer size.

Return value

Returns ERROR_SUCCESS (zero) if the call was successful, and a nonzero value if the call failed. If the buffer size passed in the BufferSize parameter is too small, or if the Buffer parameter is NULL, ERROR_MORE_DATA will be returned and the DWORD pointed to by the BufferSize parameter will be filled in with the required buffer size.

Requirements

Minimum supported client	Windows Vista
Minimum supported server	Windows Server 2008
Header	PowrProf.h
Library	PowrProf.lib
DLL	PowrProf.dll

/// <summary>
/// Enumerates the specified elements in a power scheme. This function
/// is normally called in a loop incrementing the Index parameter to
/// retrieve subkeys until they've all been enumerated.
/// </summary>
/// <param name="RootPowerKey">This parameter is reserved for future use and must be set to NULL</param>
/// <param name="SchemeGuid">The identifier of the power scheme. If this parameter is NULL,
/// an enumeration of the power policies is returned</param>
/// <param name="SubGroupOfPowerSettingsGuid">The subgroup of power settings. If this parameter is NULL,
/// an enumeration of settings under the PolicyGuid key is returned</param>
/// <param name="AccessFlags">A set of flags that specifies what will be enumerated</param>
/// <param name="Index">The zero-based index of the scheme, subgroup, or setting that is being enumerated</param>
/// <param name="Buffer">A pointer to a variable to receive the elements. If this parameter is NULL,
/// the function retrieves the size of the buffer required</param>
/// <param name="BufferSize">A pointer to a variable that on input contains the size of the buffer pointed to
/// by the Buffer parameter. If the Buffer parameter is NULL or if the BufferSize is not large enough, the
/// function will return ERROR_MORE_DATA and the variable receives the required buffer size</param>
/// <returns>Returns ERROR_SUCCESS (zero) if the call was successful, and a non-zero value if the call failed.
/// If the buffer size passed in the BufferSize parameter is too small, or if the Buffer parameter is NULL,
/// ERROR_MORE_DATA will be returned and the DWORD pointed to by the BufferSize parameter will be filled in with
/// the required buffer size.</returns>
[DllImportAttribute("powrprof.dll", EntryPoint = "PowerEnumerate", CharSet = CharSet.Auto, SetLastError = true)]
public static extern uint PowerEnumerate(IntPtr RootPowerKey, IntPtr SchemeGuid, IntPtr SubGroupOfPowerSettingsGuid, POWER_DATA_ACCESSOR AccessFlags, uint Index, ref Guid Buffer, ref uint BufferSize);

History

1/24/2011
tilellimx

Buffer Parameter

Buffer points to a GUID string