A Simple XPCOM Tutorial

// XULTesting.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "nsCOMPtr.h"
#include "../sample_xpcom/ISample.h"
#include "../sample_xpcom/Sample.h"
#include "nsServiceManagerUtils.h"

int _tmain(int argc, _TCHAR* argv[])
{
	static const char szContractId[] =
		"Your component's contract ID goes here";
	nsresult rv;

	nsCOMPtr<nsIServiceManager> servMan;

	// You Can Get the service manager several ways

	// Get Service manager : WAY 1
	//---------------------------------------
	rv = NS_GetServiceManager(getter_AddRefs(servMan));
	if (NS_FAILED(rv))
	{
		printf("ERROR: XPCOM error [%x].\n", rv);
		return -1;
	}

	//-----------End of Getting Way 1 -----------------


	// Get Service manager : WAY 2
	//--------------------------------------------------
	// Initialize XPCOM and check for failure ...
	/*rv = NS_InitXPCOM2(getter_AddRefs(servMan), nsnull, nsnull); 
	if ( NS_FAILED(rv) )
	{
		printf("Calling NS_InitXPCOM returns [%x].\n", rv);
		return -1;
	}*/
	//-----------End of Getting Way 2 --------------------

	// Get the Component object;
	nsCOMPtr<ISample> iSample;
	rv = servMan->GetServiceByContractID(SAMPLE_COMPONENT_CONTRACTID, NS_GET_IID(ISample), getter_AddRefs(iSample));	


	//if (rv == NS_ERROR_FACTORY_NOT_REGISTERED)
	if ( NS_FAILED(rv) )
	{
		NS_ShutdownXPCOM(nsnull);
		return -1;
	}
	
	int nFirstVal, nSecondVal, nResult;
	nFirstVal= 5; 
	nSecondVal = 10;
	iSample->Add(nFirstVal, nSecondVal, &nResult);
	
	_tprintf(_T("\nThe Result is : %d\n"), nResult);
	
	
	// Shutdown XPCOM 
	
	// Here also several ways you can follow

	// Explicitly Releasing ISample
	//NS_RELEASE(iSample); 

	// Or Shutdown Service manager 
	// The nsIServiceManager instance that was returned by NS_InitXPCOM2 or nsnull.
	NS_ShutdownXPCOM(nsnull);
		
	return 0;	
}