怎么从IUnknown里获取到删除文件的完整路径？

LPWSTR  __stdcall GetDeleteFileName(IUnknown* iUnknown)

{

	UINT uFileCount = 0;



	IDataObject* iDataObject = NULL;

	HRESULT hr = iUnknown->QueryInterface(IID_IDataObject, (void**)& iDataObject); //通过iUnknown接口查找IDataObject接口



	do

	{

		if (!SUCCEEDED(hr))

		{

			break;

		}



		FORMATETC fmt = { CF_HDROP, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };

		STGMEDIUM stg = { TYMED_HGLOBAL };



		if (!SUCCEEDED(iDataObject->GetData(&fmt, &stg)))

		{

			break;

		}	



		HDROP hDrop = (HDROP)GlobalLock(stg.hGlobal);



		if (hDrop == NULL)

		{

			break;

		}



		uFileCount = DragQueryFile(hDrop, 0xFFFFFFFF, NULL, 0);



		if (uFileCount <= 0)

		{

			break;

		}



		

		WPATH** ppPath = NULL;



		*ppPath = new WPATH[uFileCount];



		if (*ppPath != NULL)

		{

			for (UINT uIndex = 0; uIndex < uFileCount; uIndex++)

			{

				DragQueryFile(hDrop, uIndex, (*ppPath)[uIndex], MAX_PATH);

			}

		}

		else

		{

			uFileCount = 0;

		}



		GlobalUnlock(stg.hGlobal);



		ReleaseStgMedium(&stg);

		

		return stg.lpszFileName;



	} while (FALSE);



	return NULL;

}