C++ 编写 CorelDRAW CPG 插件例子（1）—WelcomeScreen

据我所知，这是国外论坛最早的一个例子，原贴在此：http://forum.oberonplace.com/showthread.php?t=1880&highlight=Plugins

贴上主要代码：

 #include "stdafx.h"
 #include "resource.h"

 // For Visual Studio 2003
 #import "VGCoreAuto.tlb" \
             rename("GetCommandLine", "VGGetCommandLine") \
             rename("CopyFile", "VGCore") \
             rename("FindWindow", "VGFindWindow")

 // For Visual Studio 2005
 /*
 #import "libid:95E23C91-BC5A-49F3-8CD1-1FC515597048" version("d.0") \
             rename("GetCommandLine", "VGGetCommandLine") \
             rename("CopyFile", "VGCore") \
             rename("FindWindow", "VGFindWindow")
 */

 static HINSTANCE g_hResource = NULL;

 BOOL APIENTRY DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
 {
   if(fdwReason == DLL_PROCESS_ATTACH)
   {
     g_hResource = (HINSTANCE)hinstDLL;
   }
   return TRUE;
 }

 class CWelcomeScreenPlugin : public VGCore::IVGAppPlugin
 {
 private:
   VGCore::IVGApplication *m_pApp;
   volatile ULONG m_ulRefCount;
   long m_lCookie;

   static INT_PTR CALLBACK DlgProc(HWND hDlg, UINT uMsg, WPARAM wParam, LPARAM lParam);
   void OnAppStart();

 public:
   CWelcomeScreenPlugin();

 // IUnknown
 public:
   STDMETHOD(QueryInterface)(REFIID riid, void **ppvObject);
   STDMETHOD_(ULONG, AddRef)(void) { return ++m_ulRefCount; }
   STDMETHOD_(ULONG, Release)(void)
   {
     ULONG ulCount = --m_ulRefCount;
     if(ulCount == )
     {
       delete this;
     }
     return ulCount;
   }

 // IDispatch
 public:
   STDMETHOD(GetTypeInfoCount)(UINT *pctinfo) { return E_NOTIMPL; }
   STDMETHOD(GetTypeInfo)(UINT iTInfo, LCID lcid, ITypeInfo **ppTInfo) { return E_NOTIMPL; }
   STDMETHOD(GetIDsOfNames)(REFIID riid, LPOLESTR *rgszNames, UINT cNames, LCID lcid, DISPID *rgDispId) { return E_NOTIMPL; }
   STDMETHOD(Invoke)(DISPID dispIdMember, REFIID riid, LCID lcid, WORD wFlags, DISPPARAMS *pDispParams, VARIANT *pVarResult, EXCEPINFO *pExcepInfo, UINT *puArgErr);

 // IVGAppPlugin
 public:
   STDMETHOD(raw_OnLoad)(VGCore::IVGApplication *Application);
   STDMETHOD(raw_StartSession)();
   STDMETHOD(raw_StopSession)();
   STDMETHOD(raw_OnUnload)();
 };

 CWelcomeScreenPlugin::CWelcomeScreenPlugin()
 {
   m_pApp = NULL;
   m_lCookie = ;
   m_ulRefCount = ;
 }

 STDMETHODIMP CWelcomeScreenPlugin::QueryInterface(REFIID riid, void **ppvObject)
 {
   HRESULT hr = S_OK;
   m_ulRefCount++;
   if(riid == IID_IUnknown)
   {
     *ppvObject = (IUnknown *)this;
   }
   else if(riid == IID_IDispatch)
   {
     *ppvObject = (IDispatch *)this;
   }
   else if(riid == __uuidof(VGCore::IVGAppPlugin))
   {
     *ppvObject = (VGCore::IVGAppPlugin *)this;
   }
   else
   {
     m_ulRefCount--;
     hr = E_NOINTERFACE;
   }
   return hr;
 }

 STDMETHODIMP CWelcomeScreenPlugin::Invoke(DISPID dispIdMember, REFIID riid, LCID lcid, WORD wFlags, DISPPARAMS *pDispParams, VARIANT *pVarResult, EXCEPINFO *pExcepInfo, UINT *puArgErr)
 {
   switch(dispIdMember)
   {
     case 0x0012: //DISPID_APP_START
       OnAppStart();
       break;
   }
   return S_OK;
 }

 STDMETHODIMP CWelcomeScreenPlugin::raw_OnLoad(VGCore::IVGApplication *Application)
 {
   m_pApp = Application;
   if(m_pApp)
   {
     m_pApp->AddRef();
   }
   return S_OK;
 }

 STDMETHODIMP CWelcomeScreenPlugin::raw_StartSession()
 {
   try
   {
     m_lCookie = m_pApp->AdviseEvents(this);
   }
   catch(_com_error &e)
   {
     MessageBox(NULL, e.Description(), "Error", MB_ICONSTOP);
   }
   return S_OK;
 }

 STDMETHODIMP CWelcomeScreenPlugin::raw_StopSession()
 {
   try
   {
     m_pApp->UnadviseEvents(m_lCookie);
   }
   catch(_com_error &e)
   {
     MessageBox(NULL, e.Description(), "Error", MB_ICONSTOP);
   }
   return S_OK;
 }

 STDMETHODIMP CWelcomeScreenPlugin::raw_OnUnload()
 {
   if(m_pApp)
   {
     m_pApp->Release();
     m_pApp = NULL;
   }
   return S_OK;
 }

 void CWelcomeScreenPlugin::OnAppStart()
 {
   try
   {
     m_pApp->StartupMode = VGCore::cdrStartupDoNothing;
     // To avoid 64 bit portability warning, store the long handle value into an INT_PTR
     // before casting it to HWND:
     INT_PTR nHandle = m_pApp->AppWindow->Handle;
     HWND hAppWnd = reinterpret_cast<HWND>(nHandle);
     INT_PTR nRet = DialogBoxParam(g_hResource, MAKEINTRESOURCE(IDD_WELCOME), hAppWnd, DlgProc, (LPARAM)this);
     switch(nRet)
     {
     case IDC_NEWDOC:
       m_pApp->CreateDocument();
       break;

     case IDC_LASTDOC:
       if(m_pApp->RecentFiles->Count > )
       {
         m_pApp->OpenDocument(m_pApp->RecentFiles->Item[]->FullName, );
       }
       else
       {
         MessageBox(NULL, "No documents were editied yet.", "Error", MB_ICONSTOP);
       }
       break;
     }
   }
   catch(_com_error &e)
   {
     MessageBox(NULL, e.Description(), "Error", MB_ICONSTOP);
   }
 }

 INT_PTR CALLBACK CWelcomeScreenPlugin::DlgProc(HWND hDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   if(uMsg == WM_COMMAND)
   {
     switch(LOWORD(wParam))
     {
       case IDC_NEWDOC:
         EndDialog(hDlg, IDC_NEWDOC);
         break;

       case IDC_LASTDOC:
         EndDialog(hDlg, IDC_LASTDOC);
         break;

       case IDOK:
       case IDCANCEL:
         EndDialog(hDlg, );
         break;
     }
   }
   else if(uMsg == WM_INITDIALOG)
   {
     return ;
   }
   return ;
 }

 extern "C" __declspec(dllexport) DWORD APIENTRY AttachPlugin(VGCore::IVGAppPlugin **ppIPlugin)
 {
   *ppIPlugin = new CWelcomeScreenPlugin;
   return 0x100;
 }

下载：

WelcomeScreen_Src.zip
WelcomeScreen_cpg.zip