IWMDMStorage4::GetParent

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The GetParent method retrieves the parent of the current storage.

Syntax

HRESULT GetParent(
  IWMDMStorage**  ppStorage
);

Parameters

ppStorage

[out]  Pointer to the returned parent storage object.

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. If the method fails with an error, it returns a standard error code.

Return code Description
S_OK The method succeeded and ppStorage holds the IWMDMStorage pointer to the parent object.
S_FALSE Current storage is the root storage and therefore has no parent. In this case, ppStorage is set to NULL.

Remarks

The application can traverse the complete hierarchy of the current storage by calling GetParent recursively. After the root storage is reached, GetParent returns S_FALSE and sets ppStorage to NULL.

Example

HRESULT TraverseHierarchy(IWMDMStorage *pIStorage)
{
    HRESULT hr = S_OK;
    CComPtr<IWMDMStorage4> spIStg4;

    hr = pIStorage->QueryInterface (__uuidof(IWMDMStorage4), reinterpret_cast<void**>(&spIStg4));
    if (SUCCEEDED(hr))
    {
        while ((spIStg4 != NULL))
        {
            CComPtr<IWMDMStorage> spIParent;

            hr = spIStg4->GetParent(&spIParent);
            if (FAILED(hr))
            {
                break;
            }

            //
            //Do something with spIParent.
            //
            
            if (S_FALSE != hr)
            {
                hr = spIParent->QueryInterface (__uuidof(IMDSPStorage4), reinterpret_cast<void**>(&spIStg4));
                if (FAILED(hr))
                {
                    break;
                }
            }
        }
    }

    return hr;
}

Requirements

Header: Defined in wmdm.idl.

Library: mssachlp.lib

See Also