This is preliminary documentation and subject to change.
This topic documents a feature of the Windows Media Device Manager SDK. We recommend that you migrate your application to use the Windows Portable Devices API. For more information, see the Windows Portable Devices SDK.
The GetPowerSource method reports whether the device is capable of running on batteries, external power, or both, and on which type of power source it is currently running. If the device is running on batteries, this method also reports the percentage of total power remaining in the batteries.
HRESULT GetPowerSource( DWORD* pdwPowerSource, DWORD* pdwPercentRemaining );
[out] Pointer to a DWORD that receives a value indicating the current power source for the device. The value is one of the following flags.
|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.|
[out] ** If the device is running on batteries, pdwPercentRemaining specifies a pointer to a DWORD containing the percentage of total battery power remaining.
The method returns an HRESULT. All the interface methods in Windows Media Device Manager 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 an extenstive list of possible error codes, see Error Codes.
Possible values include, but are not limited to, those in the following table.
|E_INVALIDARG||A parameter is an invalid or NULL pointer.|
|E_FAIL||An unspecified error occurred.|
|WMDM_E_NOTSUPPORTED||The device cannot report power capabilities.|
Only physical devices report power source capabilities and current power source. Software implementations of devices report no power capabilities or current power source.
This method is optional. For more information, see Mandatory and Optional Interfaces.
Header: Defined in mswmdm.h.