帮我看一下程序

我们老师给了一个做界面的程序,但我不知道这个程序是干什么的,那位高人请指教:
能否在关键地方写上几笔,小弟不甚感激!!
  程序如下://     Filename: CcItem.cpp
//  Description: Implements the CControlItem class which serves as the
//               foundation class for this applications SolidWorks
//               event handlers.
//
// -------------------------------------------------------------------//////
//////  YOU DO NOT NEED TO CHANGE THIS FILE. SEE HANDLEEVENTS.CPP FOR DETAILS
//////
#include "stdafx.h"#include <initguid.h>
#include <amapp.h>
#include <afxpriv.h>#include "CcItem.h"
#include "ExampleApp.h"
 
CControlItem::CControlItem() : CCmdTarget()
{
TheApplication->AddEvent(this);
}CControlItem::~CControlItem()
{
BOOL bres = TheApplication->RemoveEvent(this);
ASSERT (bres);
Release();
m_lpObject = NULL;
}BOOL CControlItem::OnCreate(LPDISPATCH   pObject)
{
LPUNKNOWN  pUnk = NULL;
m_lpObject = (struct IOleObject*)pObject;
//InitControlInfo(pObject); //only works for inprocess right now, no marshalling code from MicroSoft
LPPROVIDECLASSINFO2 pPCI2 = NULL; if (SUCCEEDED(m_lpObject->QueryInterface(IID_IProvideClassInfo2, (LPVOID*)&pPCI2)))
{
ASSERT(pPCI2 != NULL); if (SUCCEEDED(pPCI2->GetGUID(GUIDKIND_DEFAULT_SOURCE_DISP_IID, &m_iidEvents)))
ASSERT(!IsEqualIID(m_iidEvents, GUID_NULL));
else
ASSERT(IsEqualIID(m_iidEvents, GUID_NULL));
pPCI2->Release();
}
else
return FALSE; // No connections
if (S_OK!= pObject->QueryInterface(IID_IUnknown, (LPVOID *)&pUnk)) 
return FALSE;
LPCONNECTIONPOINTCONTAINER lpContainer;
if (S_OK!= pUnk->QueryInterface(IID_IConnectionPointContainer, (LPVOID*)&lpContainer)) 
return FALSE;
if (S_OK == lpContainer->FindConnectionPoint(m_iidEvents, &m_pConnPt)) 
{
ASSERT(m_pConnPt != NULL) ;
m_pConnPt->Advise(&m_xEventHandler, &m_dwEventConnection);
} pUnk->Release();
lpContainer->Release();
return TRUE;
}BEGIN_INTERFACE_MAP(CControlItem, CCmdTarget)
END_INTERFACE_MAP()STDMETHODIMP_(ULONG) CControlItem::XEventHandler::AddRef()
{
METHOD_PROLOGUE(CControlItem, EventHandler)
return(ULONG)pThis->ExternalAddRef();
}STDMETHODIMP CControlItem::XEventHandler::GetIDsOfNames(REFIID riid, LPOLESTR* rgszNames, unsigned int cNames, LCID lcid, DISPID* rgdispid)
{
METHOD_PROLOGUE(CControlItem, EventHandler)
ASSERT_VALID(pThis);
return ResultFromScode(E_NOTIMPL);
}STDMETHODIMP CControlItem::XEventHandler::GetTypeInfo(unsigned int itinfo, LCID lcid, ITypeInfo** pptinfo)
{
METHOD_PROLOGUE(CControlItem, EventHandler)
ASSERT_VALID(pThis);
return ResultFromScode(E_NOTIMPL);
}STDMETHODIMP CControlItem::XEventHandler::GetTypeInfoCount(unsigned int* pctinfo)
{
METHOD_PROLOGUE(CControlItem, EventHandler)
*pctinfo = 0;
return NOERROR;
}STDMETHODIMP CControlItem::XEventHandler::Invoke(DISPID dispidMember, REFIID riid, LCID lcid, unsigned short wFlags, DISPPARAMS* lpDispparams, VARIANT* pvarResult, EXCEPINFO* pexcepinfo, unsigned int* puArgErr)
{
METHOD_PROLOGUE(CControlItem, EventHandler)
ASSERT_VALID(pThis); AFX_EVENT event(AFX_EVENT::event, dispidMember, lpDispparams, pexcepinfo, puArgErr); BOOL eventHandled = pThis->OnEvent(1, &event, NULL); if (pvarResult != NULL)
VariantClear(pvarResult);
V_VT(pvarResult) = VT_BOOL;
V_BOOL(pvarResult) = eventHandled;
return event.m_hResult;
}STDMETHODIMP CControlItem::XEventHandler::QueryInterface(REFIID iid, LPVOID* ppvObj)
{
METHOD_PROLOGUE(CControlItem, EventHandler)
*ppvObj = NULL;
// || iid  == DIID_DSldWorksEvents || iid  == DIID_DPartDocEvents || iid  == DIID_DModelViewEvents)
// if(IID_IUnknown == iid || IID_IDispatch == iid || IsEqualIID(iid, pThis->m_iidEvents))
if(IID_IUnknown == iid || IID_IDispatch == iid || iid == pThis->m_iidEvents)
*ppvObj = this;
if (NULL != *ppvObj)
{
((LPUNKNOWN)*ppvObj )->AddRef();
return NOERROR;
}
return(HRESULT)pThis->ExternalQueryInterface(&iid, ppvObj);
}STDMETHODIMP_(ULONG) CControlItem::XEventHandler::Release()
{
METHOD_PROLOGUE(CControlItem, EventHandler)
return(ULONG)pThis->ExternalRelease();
}LPUNKNOWN   CControlItem::GetInterfaceHook(const void* iid)
{
if(*(IID*)iid == m_iidEvents)
 return &m_xEventHandler;
return NULL;
} void CControlItem::Release(OLECLOSE dwCloseOption)
 {
  if(m_pConnPt != NULL)
{
m_pConnPt->Unadvise(m_dwEventConnection);
m_pConnPt->Release();
}
m_pConnPt = NULL;
//COleClientItem::Release(dwCloseOption);
 }BEGIN_EVENTSINK_MAP(CControlItem, CCmdTarget)
END_EVENTSINK_MAP()// --------------------------------
//  End of CcItem.cpp
// --------------------------------