Re: Calling a Activex control from a DLL

From:

Giovanni Dicanio <giovanniDOTdicanio@REMOVEMEgmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Mon, 05 Jan 2009 15:38:32 +0100

Message-ID:

<OqcfkN0bJHA.4900@TK2MSFTNGP06.phx.gbl>

Matrixinline wrote:

I have a Activex control and I wish to call it from a DLL.

[...]

CActivex g_oActivex; // Making it Global

[...]

BOOL Method1()
{
g_oActivex.SendCommand(); // I get debug Error
here.Assertion failed.
}

Can You Please let me know How to create & initialize a Activex
Control inside a DLL.

It would be interesting to have more information about the exact "debug
Error" and assertion failure...

However, in general, if you want to instantiate some COM server (an
ActiveX is an example of a COM server), you can use code flow like this:

<code>

// Result of COM operations
HRESULT hr;

// Init COM engine
hr = CoInitialize(...)
if ( FAILED(hr) )
   ... error

// This will store the interface pointer to your COM server
IYourComServer * pComServer = NULL;

// Create an instance of the COM server object
hr = CoCreateInstance(
   CLSID_YourComServer,
   NULL,
   CLSCTX_INPROC_SERVER,
   IID_IYourComServer,
   (void **) &pComServer
);
if ( FAILED(hr) )
   ... error

// Call methods on your COM server
hr = pComServer->DoSomething(...);
if ( FAILED(hr) )
   ... error

// Cleanup COM
CoUninitialize();

</code>

Giovanni