How to use TCppWebBrowser on RAD 10.4 - c++builder-10.4-sydney

Question

The code below used to be perfect to C++Builder 6.0, but it is not compiling on RAD 10.4 Sydney.
I am not familiar with OLE controls and its classes and methods.
Can someone help me to make it work?
PogBrowser is a TCppWebBrowser.
void __fastcall TRelatPOG::ShowStream( TStream *stm )
{
try
{
if( !PogBrowser->Document )
{
PogBrowser->Navigate(L"about:blank");
while( PogBrowser->ReadyState != 4 )
Application->ProcessMessages();
}
IPersistStreamInit *psi;
TStreamAdapter *sa = new TStreamAdapter(stm,soReference);
if( sa )
{
if (SUCCEEDED(PogBrowser->Document->QueryInterface(IID_IPersistStreamInit,(void **)&psi)))
{
psi->InitNew();
psi->Load(*sa);// Compile error
psi->Release();
}
delete sa;
}
}
catch(Exception *E)
{
MessageDlg(String(E->ClassName()) + " ( " + E->Message + " )", mtError, TMsgDlgButtons() << mbOK, 0);
}
}

Answer 1

Once upon a time, TStreamAdapter used to implicitly convert to IStream*, but now it implicitly converts to _di_IStream instead (ie DelphiInterface<IStream>).
IPersistStreamInit::Save() requires IStream*, thus requires 2 conversions (TStreamAdapter -> _di_IStream -> IStream*), but C++ only allows 1 implicit conversion at a time.
So, you need to cast the TStreamAdapter to _di_IStream explicitly, which can then convert to IStream* implicitly, eg:
psi->Load(static_cast<_di_IStream>(*sa));
However, a better solution would be to let _di_IStream handle the lifetime of the TStreamAdapter to begin with, eg:
_di_IPersistStreamInit psi;
if (SUCCEEDED(PogBrowser->Document->QueryInterface(IID_IPersistStreamInit, reinterpret_cast<void**>(&psi))))
{
_di_IStream sa(*(new TStreamAdapter(stm, soReference)));
psi->InitNew();
psi->Load(sa);
}