PaulH <paul.heil@gmail.com> wrote:
I have a COM object smart pointer I'd like to share between threads
(as in the code below). The object works great in the thread it was
created in, but I get an exception when I use it in the thread I'm
sending it to.
In general, you can't do that. The interface pointer has to be
marshalled before it can be used in a different apartment. The easiest
way to do this in ATL is probably with CComGITPtr:
MyLib::IInterfacePtr m_Obj;
CMyApp::OnTimer()
{
CComGITPtr<MyLib::IInterface> gitPtr(m_Obj);
DWORD cookie = gitPtr.Detach();
m_dialog->PostMessage(MYWM_UPDATE, cookie);
}
CMyDlg::OnUpdateMsg(WPARAM wParam, LPARAM /*lParam*/)
{
DWORD cookie = static_cast<DWORD>(wParam);
CComGITPtr<MyLib::IInterface> gitPtr(cookie);
MyLib::IInterfacePtr pObj;
gitPtr.CopyTo(&pObj);
pObj->DoSomething();
}
--
With best wishes,
Igor Tandetnik
With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925