Create a simple com object.
// ConsoleApplication1.cpp : Defines the entry point for the console application. // //CoGetClassObject() simply does half the job that CoCreateInstance() does.It returns a class factory.CoCreateInstance() //then call IClassFactory::CreateInstance() and releases the IClassFactory.You would only use it if you have a need //to create many objects of a certain coclass and want to optimize that.It avoids the cost of creating and releasing //the factory over and over again. #include "stdafx.h" #include <tchar.h> #include <iostream> #include <atlcomcli.h> #include <atlbase.h> #include "F:\codes\ATLProject1\ATLProject1\ATLProject1_i.h" using namespace std; void test() { HMODULE hLib= LoadLibrary(_T("F:\\codes\\ATLProject1\\Debug\\ATLProject1.dll")); typedef HRESULT(__stdcall *PDllGetClassObject)(_In_ REFCLSID rclsid, _In_ REFIID riid, _Outptr_ LPVOID* ppv); PDllGetClassObject p = (PDllGetClassObject)GetProcAddress(hLib, ("DllGetClassObject")); IClassFactory *pFac=0; HRESULT hr = NULL; hr = p(CLSID_LiJingJing, IID_IClassFactory, (void**)&pFac); if (SUCCEEDED(hr)) { CComPtr<IClassFactory> pFac2(pFac); ILiJingJing *puk=0; hr = pFac->CreateInstance(0, IID_ILiJingJing, (void**)&puk); CComPtr<ILiJingJing> puk2(puk); if (puk2) puk2->Test(); } } int _tmain(int argc, _TCHAR* argv[]) { CoInitialize(NULL); test(); HRESULT hr = NULL; { CComPtr<ILiJingJing> puk2; hr = puk2.CoCreateInstance(CLSID_LiJingJing); if (SUCCEEDED(hr)) puk2->Test(); } ILiJingJing *puk; //hr = CoGetClassObject(CLSID_LiJingJing, CLSCTX_INPROC_SERVER, NULL, IID_ILiJingJing, (void**)&puk); hr = CoCreateInstance(CLSID_LiJingJing, NULL, CLSCTX_INPROC_SERVER, IID_ILiJingJing, (void**)&puk); if (SUCCEEDED(hr)) { puk->Test(); //do nothing puk->Release(); } else { cout << "Failed to create object" << endl; } CoUninitialize(); return 0; }
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