how to catch a _com_error

[avi123]

Hello

I have the folowing try catch

try
{
//my implementation
COMAdmin::ICOMAdminCatalogPtr spCatalog("COMAdmin.COMAdminCatalog");

HRESULT hr = spCatalog->StartApplication(m_MyComPlusApp);
}
catch(_com_error)
{

}

there are case the exceptoin is indeed thrown, and I enter the catch statment but I stiil got (before entering the catch statment) an error message & sometimes the application crash


how can I prevent that from happening?

Thanks in advacne
avi123

P.S the exception/crash happens because MyComPlusApp does not exist

[VictorN]

Have you posted your actual code?
It should be something like (this is a snippet from MSDN):

      catch( _com_error &e )
      {
         // Crack _com_error
         _bstr_t bstrSource(e.Source());
         _bstr_t bstrDescription(e.Description());

         TRACE( "Exception thrown for classes generated by #import" );
         TRACE( "\tCode = %08lx\n",      e.Error());
         TRACE( "\tCode meaning = %s\n", e.ErrorMessage());
         TRACE( "\tSource = %s\n",       (LPCTSTR) bstrSource);
         TRACE( "\tDescription = %s\n",  (LPCTSTR) bstrDescription);

         // Errors Collection may not always be populated.
         if( FAILED( hr ) )
         {
            TRACE( "*** HRESULT ***" );
            TRACE( LogCrackHR( hr )  );
         }
         ...........
     }
      catch(...)
      {
         TRACE( "*** Unhandled Exception ***" );
      }

[mudasira]

Here is a working example:

// Throw _com_error exception with our own bespoke description
void DbUtil::throwComErrorExceptionWithDescription(const wstring& desc, const _com_error& e) const
{
	//Attempt to create our own _com_error
	ICreateErrorInfo *pcerrinfo;
	IErrorInfo *perrinfo;
	HRESULT hr;
	hr = CreateErrorInfo(&pcerrinfo);
	LPOLESTR olestr = W2OLE((wchar_t*)desc.c_str());
	pcerrinfo->SetDescription(olestr);
	pcerrinfo->SetGUID(e.GUID());
	pcerrinfo->SetHelpContext(e.HelpContext());
	pcerrinfo->SetSource(e.Source());
	hr = pcerrinfo->QueryInterface(IID_IErrorInfo, (LPVOID FAR*) &perrinfo);
	if (SUCCEEDED(hr))
	{
		SetErrorInfo(0, perrinfo);
		perrinfo->Release();
		_com_error elaboratedComError(e.Error(), perrinfo);
		throw elaboratedComError;
	}
	pcerrinfo->Release();

	//fall back and throw the original _com_error
	throw e;
}

Here is the try and catch

			try
			{
				....Database command.....
			}
			catch(const _com_error& e)
			{
				wstring desc( e.Description());
				wstring errorMessage(e.ErrorMessage());

				desc += L" : ";
				desc += cmdText;
				throwComErrorExceptionWithDescription(desc, e);
			}