// the applications main entry point

int _tmain(int argc, _TCHAR* argv[])

{

// initialize the COM runtime

CoInitialize(NULL);

// a pointer to our COM class

comlibrary::IMathPtr pDotNetCOMPtr;

// create a new instance of the Math class

HRESULT hRes =pDotNetCOMPtr.CreateInstance(comlibrary::CLSID_Math);

// check it was created okay

if (hRes == S_OK)

{

// define a local to hold the result

long res = 0L;

// call the Add function

hRes =pDotNetCOMPtr->Add(1, 2, &res);

// check Add was called okay

if (hRes == S_OK)

{

// print the result

printf("The result was: %ld", res);

}

// release the pointer to the math COM class

pDotNetCOMPtr.Release();

}

// uninitialise the COM runtime

CoUninitialize();

}

示例的运行结果如下：

The result was: 3

当我们运行最后的程序时，必须保证ComLibrary.dll 与程序在同样的目录中，否则，COM 运行时会找不到文件。如果打算让这个库被多个客户端使用，那么，我强烈建议对程序集签名，并放在全局程序集缓存（Global Assembly Cache，GAC）中，这样，所有的客户端都能找到它，就不必要在第一个目录下都复制一份。