How to get a IHTMLElement pointer to the <object> tag hosting an activex control

Answer 1

Thanks to FireBreath contributor jtojanen from Finland, we finally have a solution.

The first thing is that the COM object must be registered as "Apartment", not "Single" (in the registry). Otherwise, this will not work; seems to be a bug in COM.

Then anywhere after SetClientSite is called, you can do the following:

CComQIPtr<IOleControlSite> site(m_spClientSite);
CComPtr<IDispatch> dispatch;
site->GetExtendedControl(&dispatch);
CComQIPtr<IHTMLElement2> htmlElement = dispatch;

Hope this saves someone some time; it's taken me almost 2 years to find someone who could answer this for me.

The object in htmlElement will be the <object> tag that wraps your plugin; so if you queryInterface for any of your interfaces, it should succeed, but it may not actually literally be your object, it will likely be a wrapper to your object.

Answer 2

In C#:

    public int SetSite(object site)
    {
        if (site != null)
        {
            var oleControl = (IOleControlSite)site;
            object oHtmlElement;
            oleControl.GetExtendedControl(out oHtmlElement);
            var htmlElement = (IHTMLElement2)oHtmlElement;
            ...
        }
    }