Start with the application class implementation. Change the base class so that the application class additionally derives from CExcelReadAdapter and CGXExMapHolder.

class CExrdApp : public CWinApp, public CExcelReadAdapter, public CGXExMapHolder

Define CExcelReadAdapter in your application's header (exrd.h in sample) as shown below.

// derive from the abstract CGXAppAdapter class CExcelReadAdapter : public CGXAppAdapter { public: CExcelReadAdapter(); virtual ~CExcelReadAdapter(); CGXNodeManager<CGXTabWndMgr>* CreateTabWndHolder(); virtual CDocTemplate* GetDocTemplate(CRuntimeClass* pViewClass, CRuntimeClass* pDocClass); protected: CMultiDocTemplate* m_pDocTemplate; };

Implement this class as shown below.

// Implementation of CExcelReadAdapter, // the application adapter for this application. CExcelReadAdapter::CExcelReadAdapter() { m_pDocTemplate = NULL; } CExcelReadAdapter::~CExcelReadAdapter() { if(m_pDocTemplate != NULL) { m_pDocTemplate->CloseAllDocuments(TRUE); delete m_pDocTemplate; } } // you have to override this function and return a // CDoctemplate class that is appropriate for this // view and document. The frame is unimportant. // Please note that you have to keep track of and // delete all instances of CDocTemplates that you create // here. CDocTemplate* CExcelReadAdapter::GetDocTemplate(CRuntimeClass* pViewClass, CRuntimeClass* pDocClass) { if (m_pDocTemplate != NULL) return m_pDocTemplate; m_pDocTemplate = new CMultiDocTemplate( IDR_EXRDTYPE, RUNTIME_CLASS(CExrdDoc), RUNTIME_CLASS(CGXExcelChildFrame), // custom MDI child frame RUNTIME_CLASS(CExrdView)); return m_pDocTemplate; } CGXNodeManager<CGXTabWndMgr>* CExcelReadAdapter::CreateTabWndHolder() { return new CGXNodeManager<CGXTabWndMgr>(RUNTIME_CLASS(CGXExTabWndMgr)); }

The implementation of this class does not vary much except for the part that specifies the run-time classes of the objects (shown above in bold) and can be copied from project to project for the most part. This can also be replaced with any other compatible implementation that suits your needs.

Once the maps have been defined, we have to initialize the application object to hook these maps into the read chain. This is done by adding the following lines to the application object's constructor.

SetHandlerMap(new CGXHandlerMapImpl); SetTableMap(new CGXTableMapImpl);

We do not have to add code to clean up these objects. They will be cleaned up by the application object when it goes out of scope.

Add a call to AfxOleInit() to the application InitInstance() call. This call is very important; its absence will result in inexplicable failures.

Add a member of type CGXExcelReadWnd to the dialog instance. (This can also be a class derived from this class.)

// Excel reader grid control CGXExcelReadWnd m_gridWnd;

Add the following to the OnInitDialog() code:

m_gridWnd.SubclassDlgItem(IDC_GRID, this); m_gridWnd.Initialize(); CString strPath; CFileDialog dlgFile( TRUE, _T(".xls"), NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, _T("Excel 97 Files (*.xls)|*.xls|All Files (*.*)|*.*||") ); if (dlgFile.DoModal() == IDCANCEL) return FALSE; strPath = dlgFile.GetFileName(); m_gridWnd.ReadExcelFile(strPath);

This will display a dialog at startup and, once you select an Excel file, will populate the grid with the 0^th tab of the Excel grid.

Compile the application and try opening a file. You should see the tab that you want displayed.

Change the view class so that it derives from CGXExcelGrid.

class CExtoexistView : public CGXGridView, public CGXExcelGrid

Add the following overrides to the view class as shown below:

//Excel specific overrides that delegate to CGXExcelGrid virtual BOOL OnPasteFromClipboard(const CGXRange& rg); virtual BOOL OnCheckClipboardFormat(); virtual BOOL CopyRange(const CGXRangeList& selList); virtual void OnPreExcelReadFile(); virtual void OnPostExcelReadFile(); // operations void ReadExcelFile(const CString& strFileName, UINT index = 0); void SaveExcelFile(const CString& strFileName);

The implementation for these is standard and for the most part can be copied over from one project to the other. This is shown below.

BOOL CExtoexistView::OnPasteFromClipboard(const CGXRange& rg) { return OnPasteFromClipboardImpl(rg); } BOOL CExtoexistView::OnCheckClipboardFormat() { return OnCheckClipboardFormatImpl(); } BOOL CExtoexistView::CopyRange(const CGXRangeList& selList) { return CopyRangeImpl(selList); } void CExtoexistView::OnExcelopen() { CString strPath; CFileDialog dlgFile( TRUE, _T(".xls"), NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, _T("Excel 97 Files (*.xls)|*.xls|All Files (*.*)|*.*||") ); if (dlgFile.DoModal() == IDCANCEL) return; strPath = dlgFile.GetFileName(); BOOL b = LockUpdate(TRUE); GetParam()->EnableUndo(FALSE); SetRowCount(0); SetColCount(0); // If you want to read a particular index of the worksheet // you can specify the index as the second argument. ReadExcelFile(strPath, 0); LockUpdate(b); GetParam()->EnableUndo(TRUE); Redraw(GX_UPDATENOW); } void CExtoexistView::OnExcelsave() { CString strPath; CFileDialog dlgFile( FALSE, _T(".xls"), NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, _T("Excel 97 Files (*.xls)|*.xls|All Files (*.*)|*.*||") ); if (dlgFile.DoModal() == IDCANCEL) return; strPath = dlgFile.GetFileName(); SaveExcelFile(strPath); } void CExtoexistView::ReadExcelFile(const CString& strFileName, UINT index) { // add code here to intialize from an Excel file CGXExcelWndDocAdapter docAdapt; docAdapt.SetGrid(this); OnPreExcelReadFile(); try { docAdapt.ReadExcelFile(strFileName, index); } catch(egxExcelRWFlags flags) { GX_EX_FMT_TRACE("OG Error: CGXExcelReaderImpl::ExcelWriteImpl.") CGXExRWErrorHandler::HandleError(flags); } catch(...) { GX_EX_FMT_MSG() return; } OnPostExcelReadFile(); } void CExtoexistView::OnPreExcelReadFile() { // add pre read code here CGXGridParam* pParam = GetParam(); ASSERT(pParam != NULL); pParam->EnableUndo(FALSE); } void CExtoexistView::OnPostExcelReadFile() { // add post read code here...typically common Excel // emulation code is added CGXGridParam* pParam = GetParam(); pParam->EnableUndo(TRUE); SetFloatCellsMode(gxnFloatDelayEval); ChangeStandardStyle(CGXStyle().SetWrapText(FALSE)); } void CExtoexistView::SaveExcelFile(const CString& strFileName) { CGXExcelWndDocAdapter docAdapt; docAdapt.SetGrid(this); docAdapt.SaveExcelFile(strFileName); }

As in the sample, hook the code that opens the file and saves the file to command messages.

Compile the project. Your existing view should be able to read and write Excel files as well as support rich data exchange with Excel through the clipboard.