//
// Client1
//
int main()
{
HRESULT hr ;
// Get the name of the component to use.
char name[40] ;
cout << "Enter the filename of a component to use [Cmpnt?.dll]: " ;
cin >> name ;
cout << endl ;
// Create component by calling the CreateInstance function in the DLL.
trace("Get an IUnknown pointer.") ;
IUnknown* pIUnknown = CallCreateInstance(name) ;
if (pIUnknown == NULL)
{
trace("CallCreateInstance Failed.") ;
return 1 ;
}
trace("Get interface IX.") ;
IX* pIX ;
hr = pIUnknown->QueryInterface(IID_IX, (void**)&pIX) ;
if (SUCCEEDED(hr))
{
trace("Succeeded getting IX.") ;
pIX->Fx() ; // Use interface IX.
pIX->Release() ;
}
else
{
trace("Could not get interface IX.") ;
}
trace("Release IUnknown interface.") ;
pIUnknown->Release() ;
return 0 ;
}
int APIENTRY _tWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPTSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: 在此放置代码。
HMODULE hWnd = LoadLibraryW(L"IUnknowd.dll");
if (hWnd == NULL)
{
return 1;
}
IUDllCreateObject test = (IUDllCreateObject)GetProcAddress(hWnd, "DllCreateObject");
if (NULL == test)
{
return 2;
}
IUnknow* pI = NULL;
test((void**)&pI);
IX* pX = NULL;
HRESULT hr = pI->QueryInterface(2, (void**)&pX);
if (SUCCEEDED(hr))
{
pX->PrintX();
pX->Release();
}
pI->Release();
return 0;
}
int _tmain(int argc, _TCHAR* argv[])
{
HRESULT hr;
CA *pA = new CA(); //引用计数1
//从组件查询IUnknown接口
IUnknown *pIUnknown = NULL;
hr = pA->QueryInterface(IID_IUnknown, (void**)&pIUnknown); //引用计数2
if (SUCCEEDED(hr)) //对HRESULT返回值的判断，一般采用SUCCEEDED
{
pA->Release(); //pA不再使用，引用计数1
pA = NULL; //访止再不小心使用m_pA
//从IUnknown查询IX接口
IX *pIX = NULL;
hr = pIUnknown->QueryInterface(IID_IX, (void**)&pIX); //引用计数2
if (SUCCEEDED(hr))
{
//调用IX接口的方法
pIX->Fx1();
pIX->Fx2();
}
//从IUnknown查询IY接口
IY *pIY = NULL;
hr = pIUnknown->QueryInterface(IID_IY, (void**)&pIY); //引用计数3
if (SUCCEEDED(hr))
{
//调用IY接口的方法
pIY->Fy1();
pIY->Fy1();
}
if ((void*)pIX != (void*)pIY)
{
cout << "pIX != pIY" <<endl;
}
if ((void*)pIUnknown != (void*)pIY)
{
cout << "pIUnknown != pIY" <<endl;
}
pIY->Release(); //pIY不再使用，引用计数2
pIY = NULL;
if ((void*)pIUnknown == (void*)pIX)
{
cout << "pIUnknown == pIX" <<endl;
}
//从IX查询IY
IY *pIY2 = NULL;
hr = pIX->QueryInterface(IID_IY, (void**)&pIY2); //引用计数，引用计数3
pIX->Release(); //pIX不再使用，引用计数2
pIX = NULL;
if (SUCCEEDED(hr))
{
pIY2->Fy1();
pIY2->Fy2();
}
pIY2->Release(); //pIY不再使用，引用计数1
pIY2 = NULL;
}
//目前引用计数为1，因为pIUnknown还在使用。
IX *pIX2 = NULL;
hr = pIUnknown->QueryInterface(IID_IX, (void**)&pIX2); //引用计数为2
if (SUCCEEDED(hr))
{
IX *pIX3 = NULL;
pIX3 = pIX2; //执行了赋值
pIX3->AddRef(); //由于上句执行了赋值，所以引用计数需要自增，引用计数为3
pIX3->Fx1();
pIX3->Fx2();
pIX3->Release(); //pIX3不再使用，引用计数为2
pIX3 = NULL;
}
pIX2->Release(); //pIX2不再使用，引用计数为1
pIX2 = NULL;
pIUnknown->Release(); //pIUnknown不再使用，引用计数为0，Release函数里执行了delete this，销毁组件的内存资源
pIUnknown = NULL;
//释放组件? no!
//delete pA; //不再需要写delete代码
return 0;
}
