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IWMDMStorage::GetAttributes

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The GetAttributes method retrieves the attributes of the storage.

Syntax

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

Parameters

pdwAttributes

[out]  Pointer to a DWORD specifying one or more of the following attributes, combined with a bitwise OR.

Attribute Description
WMDM_STORAGE_ATTR_FILESYSTEM This object is the top-level storage medium, for example, a storage card or some other type of on-board storage.
WMDM_STORAGE_ATTR_REMOVABLE The global storage medium is removable.
WMDM_STORAGE_ATTR_NONREMOVABLE The global storage medium is not removable.
WMDM_STORAGE_ATTR_FOLDERS The global storage medium supports folders and file hierarchy.
WMDM_STORAGE_ATTR_HAS_FILES This storage object contains at least one file as an immediate child.
WMDM_STORAGE_ATTR_HAS_FOLDERS This storage object contains at least one folder as an immediate child.
WMDM_STORAGE_ATTR_CANEDITMETADATA This storage can edit metadata.
WMDM_FILE_ATTR_FILE This is a file on the storage medium.
WMDM_FILE_ATTR_FOLDER This is a folder on the storage medium.
WMDM_FILE_ATTR_LINK This is a link that creates an association between multiple files.
WMDM_FILE_ATTR_AUDIO This file contains audio data.
WMDM_FILE_ATTR_DATA This file contains non-audio data.
WMDM_FILE_ATTR_CANPLAY This audio file can be played by the device.
WMDM_FILE_ATTR_CANDELETE This file can be deleted.
WMDM_FILE_ATTR_CANMOVE This file or folder can be moved around on the storage medium.
WMDM_FILE_ATTR_CANRENAME This file or folder can be renamed.
WMDM_FILE_ATTR_CANREAD This file can be read by the host computer.
WMDM_FILE_ATTR_MUSIC This audio file contains music.
WMDM_FILE_ATTR_AUDIOBOOK This is an audio book file.
WMDM_FILE_ATTR_VIDEO This file contains video data.
WMDM_FILE_ATTR_HIDDEN This file is hidden on the file system
WMDM_FILE_ATTR_SYSTEM This is a system file
WMDM_FILE_ATTR_READONLY This is a read-only file.
WMDM_STORAGE_ATTR_VIRTUAL This storage is virtual and does not correspond to an actual storage on the file system of the device. (Folders created based on metadata are one example of virtual storage.)
WMDM_STORAGE_IS_DEFAULT This storage is the default location for putting new digital media on the device.
WMDM_STORAGE_CONTAINS_DEFAULT This storage contains the default storage where new digital media should be placed.

pFormat

[out]  Optional pointer to a _WAVEFORMATEX structure that specifies the object's audio attributes.

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.

Example Code

The following C++ function recursively explores a storage if it is a folder with child files or folders.

void RecursiveExploreStorage(IWMDMEnumStorage* pEnumStorage)
{
    HRESULT hr = S_OK;
    CComPtr<IWMDMStorage> pStorage;
    ULONG numRetrieved = 0;
    // Loop through all storages in the current storage.
    while(pEnumStorage->Next(1, &pStorage, &numRetrieved) == S_OK && numRetrieved == 1)
    {
        // Get the name of the object. The first time this is called on a device, it will 
        // retrieve '\' as the root folder name.
        const UINT MAX_LEN = 255;
        WCHAR name[MAX_LEN];
        hr = pStorage->GetName((LPWSTR)&name, MAX_LEN);
        // TODO: Display the storage name.

    
        // Get metadata for the storage.
        if (SUCCEEDED(hr))
            GetMetadata(pStorage);

        // Find out something about the item.
        DWORD attributes = 0;
        _WAVEFORMATEX audioFormat;
        hr = pStorage->GetAttributes(&attributes, &audioFormat);
        HANDLE_HR(hr, "Got storage attributes in RecursivelyExploreStorage.","Couldn't get storage attributes in RecursivelyExploreStorage.");

        // If this is a folder, recurse into it.
        if (attributes & WMDM_FILE_ATTR_FILE)
            // TODO: Display a message indicating that this is a file.
        else if ( (attributes & WMDM_FILE_ATTR_FOLDER) &&
                  ((attributes & WMDM_STORAGE_ATTR_HAS_FILES) ||
                  (attributes & WMDM_STORAGE_ATTR_HAS_FOLDERS)) )
        {
            // TODO: Display a message indicating that this is a folder with children.
            CComPtr<IWMDMEnumStorage> pEnumSubStorage;
            hr = pStorage->EnumStorage(&pEnumSubStorage);
            RecursiveExploreStorage(pEnumSubStorage);
        }

        // Some other useful attributes to check include:
        // WMDM_FILE_ATTR_CANDELETE and WMDM_FILE_ATTR_CANPLAY and others to determine what can be done with a storage.
        // WMDM_FILE_ATTR_HIDDEN and other attributes to determine display characteristics,
        // WMDM_STORAGE_IS_DEFAULT to see if this is the default save location for new files.
        pStorage.Release();
    } // Get the next storage pointer.

e_Exit:
    return;
}

Requirements

Header: Defined in mswmdm.h.

Library: mssachlp.lib

See Also