IMDSPStorage::GetAttributes

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The GetAttributes method retrieves the attributes of this storage object.

Syntax

HRESULT GetAttributes(DWORD*pdwAttributes,_WAVEFORMATEX*pFormat);

Parameters

pdwAttributes

[out]  Pointer to a DWORD containing the attributes as defined by in the IWMDMStorage::GetAttributes method.

pFormat

[out]  Pointer to a _WAVEFORMATEX structure that is filled with attribute information about the object.

Return Values

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.

Return code Description
S_OK The method succeeded.
E_INVALIDARG The pdwAttributes parameter is an invalid or NULL pointer.
E_FAIL An unspecified error occurred.

Remarks

Evaluation of attributes is a crucial step when exposing the contents of the media device. Devices may not support hierarchical storage of data on storage media. The GetAttributes method allows the application to infer the support and format of the file system by discovering its structure through object attributes.

For example, the attributes of a top-level IMDSPStorage interface indicate a storage medium, and IMDSPEnumStorage exposes the contents of the medium. For an .mp3 file, the attributes indicate a file whose type can be determined by further examination of both the attributes and the file name. In a hierarchical medium, the attributes can indicate a directory whose contents can be exposed by IMDSPStorage::EnumStorage.

The _WAVEFORMATEX parameter is optional. If you pass a valid _WAVEFORMATEX pointer to an audio file, GetAttributes passes descriptive information back into the structure. However, if the file is not audio, the _WAVEFORMATEX parameter is ignored.

This method must be implemented. It must not return WMDM_E_NOTSUPPORTED or E_NOTIMPL. For more information, see Mandatory and Optional Interfaces.

Requirements

Header: Defined in mswmdm.h.

Library: mssachlp.lib

See Also