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IWMDMDevice::GetPowerSource

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The GetPowerSource method retrieves information about the power source and the percentage of power remaining for the device.

Syntax

HRESULT GetPowerSource(
  DWORD*  pdwPowerSource,
  DWORD*  pdwPercentRemaining
);

Parameters

pdwPowerSource

[out]  Pointer to a DWORD containing information about the power source of the device.

The possible values returned in pdwPowerSource are provided in the following table.

Flag Description
WMDM_POWER_CAP_BATTERY The media device can run on batteries.
WMDM_POWER_CAP_EXTERNAL The media device can run on external power.
WMDM_POWER_IS_BATTERY The media device is currently running on batteries.
WMDM_POWER_IS_EXTERNAL The media device is currently running on external power.
WMDM_POWER_PERCENT_AVAILABLE The percentage of power remaining was returned in pdwPercentRemaining.

pdwPercentRemaining

[out]  Pointer to a DWORD containing the percentage of power remaining in the device; however, this value is valid only if pdwPowerSource contains the WMDM_POWER_PERCENT_AVAILABLE flag.

Return Values

The method returns an HRESULT. All the interface methods in Windows Media Device Manager and service provider can return any of the following classes of error codes:

  • Standard COM error codes
  • Windows error codes converted to HRESULT values
  • Windows Media Device Manager error codes

For a complete list of possible error codes, see Error Codes.

Possible values include, but are not limited to, those in the following table.

Return code Description
E_INVALIDARG One of the parameters is an invalid or NULL pointer.
WMDM_E_NOTSUPPORTED The device cannot provide this information.
E_FAIL An unspecified error occurred.

Remarks

Only physical devices report power source capabilities and current power source. Software implementations of devices report neither capabilities nor current power source.

Requirements

Header: Defined in wmdm.idl.

Library: mssachlp.lib

See Also