COM 简单模型

原创

wangzai9931 2009-06-08 23:18:34 博主文章分类：C/C++/VC ©著作权

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1.实现一个COM组件

1.）使用VC6建立Win32 Dll工程

2.）定义接口

interface IX : public IUnknown
{
                virtual HRESULT __stdcall FunX()=0;
};

interface IY : public IUnknown
{
                virtual HRESULT __stdcall FunY()=0;
};

interface IZ : public IUnknown
{
                virtual HRESULT __stdcall FunZ()=0;
};

extern "C" const CLSID CLSID_CA =
        { 0xd7153f69, 0x9668, 0x47d7,
        { 0xb9, 0xc8, 0xb2, 0x1a, 0x2b, 0xbe, 0xc5, 0x44 } };

// {2F8AD6CD-E631-4120-8F72-23C5E96921DE}
extern "C" const IID IID_IX =
        { 0x2f8ad6cd, 0xe631, 0x4120,
        { 0x8f, 0x72, 0x23, 0xc5, 0xe9, 0x69, 0x21, 0xde } } ;

// {B6985A8F-6EA0-4a58-B3DC-9E14BCB81041}
extern "C" const IID IID_IY =
        { 0xb6985a8f, 0x6ea0, 0x4a58,
        { 0xb3, 0xdc, 0x9e, 0x14, 0xbc, 0xb8, 0x10, 0x41 } };

// {311FD901-390D-4fe1-AE83-96176D0A1991}
extern "C" const IID IID_IZ =
        { 0x311fd901, 0x390d, 0x4fe1,
        { 0xae, 0x83, 0x96, 0x17, 0x6d, 0xa, 0x19, 0x91 }};

3.)实现接口 IX，IY

class CA : public IX,public IY
{
public:
                CA();
                virtual ~CA();

public:
                // Interface : IUnknown
                virtual HRESULT __stdcall QueryInterface(const IID& iid, void** ppv) ;
                virtual ULONG __stdcall AddRef() ;
                virtual ULONG __stdcall Release() ;

                // Interface : IX
                virtual HRESULT __stdcall FunX();

                // Interface : IY
                virtual HRESULT __stdcall FunY();

private:
                long        m_lnRef ;
};

CA::CA()
{
                m_lnRef = 1 ;
                InterlockedIncrement(&g_lnClsRef) ;
}

CA::~CA()
{
                InterlockedDecrement(&g_lnClsRef) ;
}

HRESULT __stdcall CA::QueryInterface(const IID& iid, void** ppv)
{
                if(iid == IID_IUnknown)
                {
                                *ppv = static_cast<IX *>(this) ;
                }
                else        if(iid == IID_IX)
                {
                                *ppv = static_cast<IX *>(this) ;
                }
                else        if(iid == IID_IY)
                {
                                *ppv = static_cast<IY *>(this) ;
                }
                else
                {
                                *ppv = NULL ;
                                return E_NOINTERFACE ;
                }

                reinterpret_cast<IUnknown*>(*ppv)->AddRef();

                return S_OK ;
}

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

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

4.）实现IClassFactory

class CFactory : public IClassFactory
{
public:
                CFactory();
                virtual ~CFactory();

public:
                // Interface : IUnknown
                virtual HRESULT __stdcall QueryInterface(
                                                const IID& iid,
                                                void** ppv
                                                ) ;

                virtual ULONG         __stdcall AddRef() ;
                virtual ULONG         __stdcall Release() ;

                // Interface : IClassFactory
                virtual HRESULT __stdcall CreateInstance(
                                                IUnknown* pUnknownOuter,
                                                const IID& iid,
                                                void** ppv
                                                ) ;

                virtual HRESULT __stdcall LockServer(BOOL bLock) ;

private:
                long        m_lnRef ;
};

CFactory::CFactory()
{
                m_lnRef = 1 ;
}

CFactory::~CFactory()
{
}

// Interface : IUnknown
HRESULT __stdcall CFactory::QueryInterface(const IID& iid, void** ppv)
{
                if ((iid == IID_IUnknown) || (iid == IID_IClassFactory))
                {
                                *ppv = static_cast<IClassFactory*>(this) ;
                }
                else
                {
                                *ppv = NULL ;
                                return E_NOINTERFACE ;
                }

                reinterpret_cast<IUnknown*>(*ppv)->AddRef() ;

                return S_OK ;
}

ULONG         __stdcall CFactory::AddRef()
{
                return InterlockedIncrement(&m_lnRef) ;
}

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

                return m_lnRef ;
}

// Interface : IClassFactory
HRESULT __stdcall CFactory::CreateInstance(IUnknown* pUnknownOuter,
                                                                                                                                 const IID& iid,
                                                                                                                                 void** ppv)
{
                CA * pA = new CA ;
                if(pA == NULL)
                {
                                return E_OUTOFMEMORY ;
                }

                HRESULT hRet = pA->QueryInterface(iid,ppv);

                pA->Release();

                return hRet ;
}

HRESULT __stdcall CFactory::LockServer(BOOL bLock)
{
                if (bLock)
                {
                                InterlockedIncrement(&g_lnFacRef) ;
                }
                else
                {
                                InterlockedDecrement(&g_lnFacRef) ;
                }
                return S_OK ;

5.)实现注册类

代码见附件.

6.）导出接口函数

STDAPI DllGetClassObject(
                                                const CLSID& clsid,
                                                const IID& iid,
                                                void** ppv
                                                )
{
                if (clsid != CLSID_CA)
                {
                                return CLASS_E_CLASSNOTAVAILABLE ;
                }

                CFactory* pFactory = new CFactory ;
                if (pFactory == NULL)
                {
                                return E_OUTOFMEMORY ;
                }

                HRESULT hRet = pFactory->QueryInterface(iid, ppv) ;
                pFactory->Release() ;

                return hRet ;
}

STDAPI DllCanUnloadNow()
{
                if(g_lnClsRef == 0 && g_lnFacRef == 0)
                {
                                return S_OK ;
                }
                else
                {
                                return S_FALSE ;
                }
}

//== Register Info===============================
LPCTSTR g_ptszName            = _T("PENGY Test Com.");
LPCTSTR g_ptszVerIndProgID    = _T("PENGY.Test");
LPCTSTR g_ptszProgID            = _T("PENGY.Test.1");
//== Register Info===============================

STDAPI DllRegisterServer()
{
                TCHAR    pszPath[1024];

                if(0 == GetModuleFileName(g_hmodSelf,pszPath,1024))
                {
                                return S_FALSE ;
                }

                // 将相关信息写入注册表.
                return CRegisterAPI::RegisterServer(
                                                                                                pszPath,
                                                                                                CLSID_CA,
                                                                                                g_ptszName,
                                                                                                g_ptszVerIndProgID,
                                                                                                g_ptszProgID
                                                                                                ) ;

}

STDAPI DllUnregisterServer()
{
                // 删除相关的注册信息
                return CRegisterAPI::UnregisterServer(
                                                                                            CLSID_CA,
                                                                                            g_ptszVerIndProgID,
                                                                                            g_ptszProgID
                                                                                            ) ;
}

7.）编译生成ComServer.dll

8.）注册和卸载

卸载：regsvr32 /u ComServer.dll

9.）完成

2. 实现一个COM客户程序

1.）初始化COM

CoInitialize(NULL);

2.）创建COM对象

IUnknown * pIUnknown = NULL ;
CoCreateInstance(
                CLSID_CA,        // 类ID
                NULL,        // 聚合时使用
                CLSCTX_INPROC_SERVER, // 组件类别(进程内组件)
                IID_IUnknown,
                (void**)& pIUnknown
);

3.）查询接口并使用接口提供的功能

IX * pIX = NULL ;
HRESULT hRet = pIUnknown->QueryInterface(IID_IX,(void**)&pIX);
if(SUCCEEDED(hRet))
{
                pIX->FunX() ;
                // …
                pIX->Release();
}

4.）卸载COM库

CoUninitialize();