COM in C++

[khanusman12]

So I am trying to write a program that will instantiate and control a COM object, in this case a telescope dome simulator (DomeSim.exe). So for example, if I tell the program to park the dome, the simulator will park etc. Using COM in C++ is quite annoying and difficult, and at the moment I am just trying to implement one method, and even still I can't tell if I'm doing it right as I'm just going off online tutorials and examples. Here is the Code below.

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <windows.h>
#include <C:\Users\Usman-Khan\Desktop\dome_script\DomeSimulator.h>
#import <C:\Users\Usman-Khan\Desktop\dome_script\DomeSim.exe>

//-----------------------------------------------------------------------------
// Declarations
//-----------------------------------------------------------------------------

const IID DomeSimulator::IID_Dome =
{ 0xdb93d7ba, 0xb7f6, 0x4734, { 0x92, 0x34, 0x3e, 0x39, 0xa1, 0xa5, 0xa5, 0xa3 }} ;
;

/******************************************************************************
******************************************************************************/
DomeSimulator::DomeSimulator()
{
initializeCOM();
}

/******************************************************************************
******************************************************************************/
DomeSimulator::~DomeSimulator()
{
uninitializeCOM();
}

/******************************************************************************
******************************************************************************/
void DomeSimulator::initializeCOM()
{
CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
pIUnknown = NULL;
//m_IDome = NULL;
}
/******************************************************************************
******************************************************************************/
bool DomeSimulator::loadCOM()
{
if( pIUnknown != NULL )
{
pIUnknown->Release();
pIUnknown = NULL;
}
CLSID ASCOMDomeSimulator;
CLSIDFromProgID( L"DomeSim.Dome", &ASCOMDomeSimulator );
HRESULT hr = CoCreateInstance(ASCOMDomeSimulator, NULL, CLSCTX_ALL, IID_IUnknown, reinterpret_cast<void**>(&pIUnknown));
if (SUCCEEDED(hr))
{
//hr = pIUnknown->QueryInterface(IID_Dome,(void**)&m_IDome );
return true;
}
else
{
return false;
}
}
/******************************************************************************
******************************************************************************/
void DomeSimulator::uninitializeCOM()
{
//if( m_IDome != NULL )
//{
// m_IDome->Release();
// m_IDome = NULL;
//}
if( pIUnknown != NULL )
{
pIUnknown->Release();
pIUnknown = NULL;
}
CoUninitialize();
}
/******************************************************************************
******************************************************************************/
bool DomeSimulator::get_AtHome() const
{
//if( m_IDome != NULL )
//{
// return m_IDome->get_AtHome();
//}
return 0;
}
/******************************************************************************
******************************************************************************/
//-----------------------------------------------------------------------------
// Execution
//-----------------------------------------------------------------------------
int main(void)
{
DomeSimulator instance;
bool home = &DomeSimulator::get_AtHome;
return home;
};
)

That was the main code, while the code below is the wrapper file DomeSimulator.h

#include <windows.h>
#include <string>
#include <vector>
//int *pIUnknown;

//namespace DomeSim {
// struct _Domes{};
//};

//Wrapper Class
class DomeSimulator
{
public:
DomeSimulator();
~DomeSimulator();
void initializeCOM();
bool loadCOM();
void uninitializeCOM();
bool get_AtHome() const;
private:
static const IID IID_Dome;
//DomeSim::_Domes *m_IDome;
IUnknown *pIUnknown;
};

So the main method I'm trying to get to use atm is the get_AtHome method, which should be simple enough. I just want to know if I am going about this the right way, and what I need to do to fix it as COM is quite confusing.

[freddie1]

Using the #import directive is the accepted way to go about it in C++.

I wish I could help, as I'm kind of a COM guy, but I don't do it that way. I use my own rather low level direct techniques, which wouldn't work for you unless you've devoted your life to COM, as I have :).

The person here who's knowledgable about using the #import directive with COM in C++ is Andy Weskin. Possibly others too, but I know Andy is real familiar with it. He might be busy and not have the time to help though. About the only help I can offer is the suggestion to learn how to use code tags. Nobody wants to look at unformatted code.

[alexeyn]

that that you'd put here doesnt looks like ole
real ole looks like that http://fullproject.googlecode.com/svn/trunk/code/SDK/WinAPI%20Programming/CHAP20/


Code from Petzold book



bool DomeSimulator::get_AtHome() const
.......
bool home = &DomeSimulator::get_AtHome

not bad


You just can try to invoke something like "microsoft rich textbox" to begin. For example