COM ：基本的接口(IX,IY), 组件的实现(CA)，以及对组件的调用

#include "pch.h"
#include

#include

using namespace std;

void trace(const char* msg) { cout << msg << endl; }

//Interfaces start
interface IX :IUnknown
{
virtual void __stdcall Fx() = ;
};

interface IY :IUnknown
{
virtual void __stdcall Fy() = ;
};

interface IZ :IUnknown
{
virtual void __stdcall Fz() = ;
};

//Forward references for GUIDs
extern const IID IID_IX;
extern const IID IID_IY;
extern const IID IID_IZ;
//Interface end

//component start
class CA :public IX, public IY
{
LONG m_cRef;
virtual HRESULT __stdcall QueryInterface(const IID& iid, void** ppv);
virtual ULONG __stdcall AddRef();
virtual ULONG __stdcall Release();

        virtual void \_\_stdcall Fx() { cout << "Fx function" << endl; }  
    virtual void \_\_stdcall Fy() { cout << "Fy function" << endl; }  复制

public:
CA();
~CA() { trace("CA: Destory Self"); }
};

CA::CA()
{
trace("CA: Constrator Self");
m_cRef = ;
}

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

ULONG __stdcall CA::AddRef()
{
InterlockedIncrement(&m_cRef);
cout << "CA AddRef -- Ref:" << m_cRef << endl;
return m_cRef;
}

ULONG __stdcall CA::Release()
{

        if (InterlockedDecrement(&m\_cRef) == )  
        {  
            delete this;  
            return ;  
        }  
    cout << "CA ReleaseRef -- Ref:" << m\_cRef << endl;  
    return m\_cRef;  
}复制

IUnknown* CreateInstance()
{
IUnknown* pI = static_cast(new CA);
pI->AddRef();
return pI;
}

// {05464095-EC3A-45b3-8E0C-D1793FBDF13D}
static const IID IID_IX =
{ 0x5464095, 0xec3a, 0x45b3, { 0x8e, 0xc, 0xd1, 0x79, 0x3f, 0xbd, 0xf1, 0x3d } };

// {39696224-3AE3-4b46-B056-99359CAC6CA9}
static const IID IID_IY =
{ 0x39696224, 0x3ae3, 0x4b46, { 0xb0, 0x56, 0x99, 0x35, 0x9c, 0xac, 0x6c, 0xa9 } };

// {6684A06D-64B8-46f3-9988-CDC119E18165}
static const IID IID_IZ =
{ 0x6684a06d, 0x64b8, 0x46f3, { 0x99, 0x88, 0xcd, 0xc1, 0x19, 0xe1, 0x81, 0x65 } };
//component end

//client start
int main(int argc, char* argv[])
{
HRESULT hr;
trace("Client: Get an IUnknown pointer");
IUnknown* pIUnknown = CreateInstance();
IX* pIx = NULL;
trace("Client: Get Interface IX");
hr = pIUnknown->QueryInterface(IID_IX, (void**)&pIx);
if (SUCCEEDED(hr))
{
trace("Client: Succeed Get Interface IX");
pIx->Fx();
}

        IY\* pIY = NULL;  
    hr = pIUnknown->QueryInterface(IID\_IY, (void\*\*)&pIY);  
    pIUnknown->Release();  
    if (SUCCEEDED(hr))  
        {  
            trace("Client: Succeed GetInterface IY");  
            pIY->Fy();  
            pIY->Release();  
        }

        //Query IY from IX  
        IY\* pIYfromIX = NULL;  
    hr = pIx->QueryInterface(IID\_IY, (void\*\*)&pIYfromIX);  
    if (SUCCEEDED(hr))  
        {  
            trace("Client: Succeed GetInterfae IY from pIX");  
            pIYfromIX->Fy();  
            pIYfromIX->Release();  
        }  
    pIx->Release();  
    //delete component  
    //    delete pIUnknown;  
        return ;  
}  复制

//client end

参考资料:

1、COM程序的简单实现（COM技术内幕笔记之一）

2、COM组件开发（一）—— 对象与接口