// Serialisieren/DeSerialisieren eines IUnknowns
// in diesem Falle ein IDataObject
HRESULT CreateStreamOnHGlobalFromIUnknown (
IUnknown *pIUnk, REFCLSID rClsID, IStream **ppIStream)
{
ASSERT(NULL != pIUnk);
ASSERT(NULL != ppIStream);
*ppIStream = NULL;
try {
// neuen Stream anlegen, kreiert eine neuen Memoryblock der Größe NULL
// wird selbstständig wieder freigegen (true)
WStream IStream;
THROW_FAILED_HRESULT(CreateStreamOnHGlobal (NULL, true, IStream.ppi()));
// den Enumerator wegschreiben
WPersistStream IPersStr (pIUnk); // throws hr
THROW_FAILED_HRESULT(OleSaveToStream (IPersStr, IStream));
// wieder zurück positionieren
LARGE_INTEGER li;
LISet32 (li, 0L);
THROW_FAILED_HRESULT(IStream -> Seek (li, STREAM_SEEK_SET, NULL));
*ppIStream = IStream.detach();
}
catch (_com_error &e)
{
return _COM_ERROR(e);
}
return S_OK;
}
///////////////////////////////////////////////////////////////////////////////
// Schreiben/Lesen eines Variant
HRESULT SetVariantData (CComVariant &rv, IDataObject *pIDO, const FORMATETC *pcfe)
{
// Stream mit Variant generieren
WStream IStream;
HRESULT hr = CreateStreamOnHGlobal (NULL, true, IStream.ppi());
if (FAILED(hr)) return hr;
// Variant dort rein schreiben
hr = rv.WriteToStream (IStream);
if (FAILED(hr)) return hr;
LARGE_INTEGER li;
LISet32(li, 0L);
hr = IStream -> Seek (li, SEEK_SET, NULL);
if (FAILED(hr)) return hr;
// diesen Stream im DataObject setzen
STGMEDIUM stg;
stg.tymed = TYMED_ISTREAM;
stg.pstm = IStream.detach();
stg.pUnkForRelease = NULL;
hr = pIDO -> SetData ((FORMATETC *)pcfe, &stg, true);
if (FAILED(hr)) {
ReleaseStgMedium (&stg);
return hr;
}
return S_OK;
}
// Hinzufügen eines EnumLONG zu einem IDataObject -----------------------------
HRESULT SetEnumLONGData (IEnum<LONG> *pEnum, REFCLSID rClsID, IDataObject *pDataObj)
{
ASSERT(pEnum);
ASSERT(pDataObj);
// Stream mit EnumLONG generieren
WStream IStream;
HRESULT hr = CreateStreamOnHGlobalFromIUnknown (pEnum, rClsID, IStream.ppi());
if (FAILED(hr)) return hr;
// diesen Stream im DataObject setzen
STGMEDIUM stg;
stg.tymed = TYMED_ISTREAM;
stg.pstm = IStream.detach();
stg.pUnkForRelease = NULL;
hr = pDataObj -> SetData ((FORMATETC *)&c_feSelectedObjects, &stg, true);
if (FAILED(hr)) return hr;
return NOERROR;
}
