cmpnt3.cpp

inside com的源代码

//
// Cmpnt3.cpp
// To compile, use: cl /LD Cmpnt3.cpp GUIDs.cpp UUID.lib Cmpnt3.def
//
#include <iostream.h>
#include <objbase.h>

#include "Iface.h"

void trace(const char* msg) { cout << "Component 3:\t" << msg << endl ;}

//
// Component
//
class CA : public IX,
           public IY,
           public IZ
{
	// IUnknown implementation
	virtual HRESULT __stdcall QueryInterface(const IID& iid, void** ppv) ;			
	virtual ULONG __stdcall AddRef() ;
	virtual ULONG __stdcall Release() ;

	// Interface IX implementation
	virtual void __stdcall Fx() { cout << "Fx" << endl ;}

	// Interface IY implementation
	virtual void __stdcall Fy() { cout << "Fy" << endl ;}

	// Interface IZ implementation
	virtual void __stdcall Fz() { cout << "Fz" << endl ;}

public:
	// Constructor
	CA() : m_cRef(0) {}

	// Destructor
	~CA() { trace("Destroy self.") ;}

private:
	long m_cRef ;
} ;

HRESULT __stdcall CA::QueryInterface(const IID& iid, void** ppv)
{ 	
	if (iid == IID_IUnknown)
	{
		trace("Return pointer to IUnknown.") ;
		*ppv = static_cast<IX*>(this) ;
	} 
	else if (iid == IID_IX)
	{
		trace("Return pointer to IX.") ;
		*ppv = static_cast<IX*>(this) ;
	}
	else if (iid == IID_IY)
	{
		trace("Return pointer to IY.") ;
		*ppv = static_cast<IY*>(this) ;
	}
	else if (iid == IID_IZ)
	{
		trace("Return pointer to IZ.") ;
		*ppv = static_cast<IZ*>(this) ;
	}
	else
	{  	   
		trace("Interface not supported.") ;
		*ppv = NULL ;
		return E_NOINTERFACE ;
	}
	reinterpret_cast<IUnknown*>(*ppv)->AddRef() ; 
	return S_OK ;
}

ULONG __stdcall CA::AddRef()
{
	return InterlockedIncrement(&m_cRef) ;
}

ULONG __stdcall CA::Release() 
{
	if (InterlockedDecrement(&m_cRef) == 0)
	{
		delete this ;
		return 0 ;
	}
	return m_cRef ;

}

//
// Creation function
//
extern "C" IUnknown* CreateInstance()
{
	IUnknown* pI = static_cast<IX*>(new CA) ;
	pI->AddRef() ;
	return pI ;
}