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DevicePowerEnumDevices function (powrprof.h)

  • Article

Enumerates devices on the system that meet the specified criteria.

Syntax

BOOLEAN DevicePowerEnumDevices(
  [in]            ULONG  QueryIndex,
  [in]            ULONG  QueryInterpretationFlags,
  [in]            ULONG  QueryFlags,
  [out, optional] PBYTE  pReturnBuffer,
  [in, out]       PULONG pBufferSize
);

Parameters

[in] QueryIndex

The index of the requested device. For initial calls, this value should be zero.

[in] QueryInterpretationFlags

The criteria applied to the search results.

Value Meaning
DEVICEPOWER_HARDWAREID
0x80000000
 Return a hardware ID string rather than friendly device name.
DEVICEPOWER_FILTER_DEVICES_PRESENT
0x20000000
 Ignore devices not currently present in the system.
DEVICEPOWER_AND_OPERATION
0x40000000
 Perform an AND operation on QueryFlags.
DEVICEPOWER_FILTER_WAKEENABLED
0x08000000
 Check whether the device is currently enabled to wake the system from a sleep state.
DEVICEPOWER_FILTER_ON_NAME
0x02000000
 Find a device whose name matches the string passed in pReturnBuffer and check its capabilities against QueryFlags.

[in] QueryFlags

The query criteria.

Value Meaning
PDCAP_D0_SUPPORTED
0x00000001
 The device supports system power state D0.
PDCAP_D1_SUPPORTED
0x00000002
 The device supports system power state D1.
PDCAP_D2_SUPPORTED
0x00000004
 The device supports system power state D2.
PDCAP_D3_SUPPORTED
0x00000008
 The device supports system power state D3.
PDCAP_S0_SUPPORTED
0x00010000
 The device supports system sleep state S0.
PDCAP_S1_SUPPORTED
0x00020000
 The device supports system sleep state S1.
PDCAP_S2_SUPPORTED
0x00040000
 The device supports system sleep state S2.
PDCAP_S3_SUPPORTED
0x00080000
 The device supports system sleep state S3.
PDCAP_S4_SUPPORTED
0x01000000
 The device supports system sleep state S4.
PDCAP_S5_SUPPORTED
0x02000000
 The device supports system sleep state S5.
PDCAP_WAKE_FROM_D0_SUPPORTED
0x00000010
 The device supports waking from system power state D0.
PDCAP_WAKE_FROM_D1_SUPPORTED
0x00000020
 The device supports waking from system power state D1.
PDCAP_WAKE_FROM_D2_SUPPORTED
0x00000040
 The device supports waking from system power state D2.
PDCAP_WAKE_FROM_D3_SUPPORTED
0x00000080
 The device supports waking from system power state D3.
PDCAP_WAKE_FROM_S0_SUPPORTED
0x00100000
 The device supports waking from system sleep state S0.
PDCAP_WAKE_FROM_S1_SUPPORTED
0x00200000
 The device supports waking from system sleep state S1.
PDCAP_WAKE_FROM_S2_SUPPORTED
0x00400000
 The device supports waking from system sleep state S2.
PDCAP_WAKE_FROM_S3_SUPPORTED
0x00800000
 The device supports waking from system sleep state S3.
PDCAP_WARM_EJECT_SUPPORTED
0x00000100
 The device supports warm eject.

[out, optional] pReturnBuffer

Pointer to a buffer that receives the requested information.

[in, out] pBufferSize

The size, in bytes, of the return buffer.

Note  If pReturnBuffer is NULL, pBufferSize will be filled with the size needed to return the data.
 

Return value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero.

Remarks

The values of the QueryFlags parameter may be combined to query for devices that support two or more criteria. For example; if PDCAP_D3_SUPPORTED | PDCAP_D1_SUPPORTED is passed as the QueryFlags parameter, the function will query for devices that support either D3 or D1.

QueryFlags also may be combined with QueryInterpretationFlags set to DEVICEPOWER_AND_OPERATION to produce a query of devices that support all of the requested criteria. For example; if PDCAP_D3_SUPPORTED | PDCAP_D1_SUPPORTED is passed as the QueryFlags parameter and DEVICEPOWER_AND_OPERATION is passed as the QueryInterpretationFlags parameter, the function will query devices that support both D3 and D1.

Examples

For an example that uses this function, see Using the Device Power API.

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Target Platform Windows
Header powrprof.h
Library PowrProf.lib
DLL PowrProf.dll

See also

Device Power Management