IWMSDirectory::GetChildInfo

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IWMSDirectory::GetChildInfo

The GetChildInfo method retrieves information about a specific media element in a directory.

Syntax

  HRESULT GetChildInfo(
  DWORD  dwIndex,
  WMSDirectoryEntryInfo*  pInfo
);

Parameters

dwIndex

[in] DWORD containing the index number of the media element.

pInfo

[out] Pointer to a WMSDirectoryEntryInfo structure that contains information about the media element.

Return Values

If the method succeeds, it returns S_OK. If it fails, it returns an HRESULT error code.

Return code Description
S_FALSE No media element corresponds to the index provided.

Remarks

The information that can be retrieved from the GetChildInfo method is dependent upon your implementation.

Example Code

The following example retrieves the name and size of a file from a linked list of user-defined CDirectoryInfo classes. The linked list can be created when the server calls IWMSDataSourcePlugin::OpenDirectory.

// In this example, the CDirectoryInfo class contains the 
// following data members.
CDirectoryInfo() 
{ 
    m_cRef = 1;             // Reference count.
    m_pszwName = NULL;      // File name.
    m_qwSize = 0;           // File size.
    m_pNext = NULL;         // Pointer to the next CDirectoryInfo.
}

HRESULT STDMETHODCALLTYPE 
CDirectory::GetChildInfo( 
                    DWORD dwIndex,
                    WMSDirectoryEntryInfo *pInfo
                    )
{
    HRESULT hr = S_OK;
    DWORD dwUrlLength;

    // Advance to the indicated position in the directory.
    while ( ( m_dwItemNum < dwIndex ) && ( NULL != m_pRecentChild ) )
    {
        m_pRecentChild = m_pRecentChild->m_pNext;
        m_dwItemNum++;
    } 
    
    // Quit if you are at the end of the directory.
    if( NULL == m_pRecentChild )
    {
        hr = S_FALSE;
        goto exit;
    }

    // Copy the name of the directory from the CDirectoryInfo
    // object into the WMSDirectoryEntryInfo structure.
    dwUrlLength = wcslen( m_pRecentChild->m_pszwName ) + 1;
    pInfo->pstrName = ( LPOLESTR ) CoTaskMemAlloc( 
                            sizeof(OLECHAR) * dwUrlLength );
    wcscpy_s( pInfo->pstrName, dwUrlLength, m_pRecentChild->m_pszwName );

    // Copy the file size from the CDirectoryInfo object
    // into the WMSDirectoryEntryInfo structure.
    pInfo->qwSize = m_pRecentChild->m_qwSize;

EXIT:
    return( hr );

}

Requirements

Header: datacontainer.h.

Library: WMSServerTypeLib.dll.

Platform: Windows Server 2003, Enterprise Edition; Windows Server 2003, Datacenter Edition; Windows Server 2008.

See Also

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