使用MFC插入Excel工作表并实现自动化

摘要
这篇文章讲述了如何使用MFC将Excel工作表插入到SDI视图中。 
文章包括插入工作表并将文字添加到A1单元格的详细步骤，每一步都有详细说明。 虽然你可以直接将代码插入到你的程序中，
但理解这些例子你才会真正受益。 

更多信息

以下是创建这个MFC应用程序的步骤： 
1.使用AppWizard创建一个新的MFC AppWizard(EXE)工程，命名为"Embed_Excel" 
2.选择单文档视图(SDI)结构，在第3步中需要选中Container,以提供容器支持。 
其它都为默认。 

产生以下类： 

应用类: CEmbed_ExcelApp in Embed_Excel.h and Embed_Excel.cpp 
框架类: CMainFrame in MainFrm.h and MainFrm.cpp 
文档类: CEmbed_ExcelDoc in Embed_ExcelDoc.h and Embed_ExcelDoc.cpp 
视图类: CEmbed_ExcelView in Embed_ExcelView.h and Embed_ExcelView.cpp 
容器类: CEmbed_ExcelCntrItem in CntrItem.h and CntrItem.cpp 

3.在VIEW菜单中，选ClassWizard,选Automation选项卡,选Add Class,选择From a TypeLibrary, 选中Microsoft Excel 97/2000 类型库,Excel8.olb或Excel9.olb会将类型库中的所有类添加到你的工程中。

4.在CntrItem.h中添加如下行： 

LPDISPATCH GetIDispatch(); 


5.然后在CntrItem.cpp中添加GetIDispatch方法         

          

   示例代码
   -----------


      /*******************************************************************
      *   This method returns the IDispatch* for the application linked to
      *   this container.
      ********************************************************************/ 
      LPDISPATCH CEmbed_ExcelCntrItem::GetIDispatch()
      {
         //The this and m_lpObject pointers must be valid for this function
         //to work correctly. The m_lpObject is the IUnknown pointer to
         // this object.
         ASSERT_VALID(this);
         ASSERT(m_lpObject != NULL);

         LPUNKNOWN lpUnk = m_lpObject;

         //The embedded application must be running in order for the rest
         //of the function to work.
         Run();

         //QI for the IOleLink interface of m_lpObject.
         LPOLELINK lpOleLink = NULL;
         if (m_lpObject->QueryInterface(IID_IOleLink,
            (LPVOID FAR*)&lpOleLink) == NOERROR)
         {
            ASSERT(lpOleLink != NULL);
            lpUnk = NULL;

            //Retrieve the IUnknown interface to the linked application.
            if (lpOleLink->GetBoundSource(&lpUnk) != NOERROR)
            {
               TRACE0("Warning: Link is not connected!\n");
               lpOleLink->Release();
               return NULL;
            }
            ASSERT(lpUnk != NULL);
         }

         //QI for the IDispatch interface of the linked application.
         LPDISPATCH lpDispatch = NULL;
         if (lpUnk->QueryInterface(IID_IDispatch, (LPVOID FAR*)&lpDispatch)
            !=NOERROR)
         {
            TRACE0("Warning: does not support IDispatch!\n");
            return NULL;
         }

         //After assuring ourselves it is valid, return the IDispatch
         //interface to the caller.
         ASSERT(lpDispatch != NULL);
         return lpDispatch;
      } 

6.在Embed_ExcelView.h中添加如下行:

      void EmbedAutomateExcel(); 

7.然后在Embed_ExcelView.cpp中添加EmbedAutomateExcel方法:

示例代码
   -----------

      /********************************************************************
      *   This method encapsulates the process of embedding an Excel
      *   Worksheet in a View object and automating that worksheet to add
      *   some text to cell A1.
      ********************************************************************/ 
      void CEmbed_ExcelView::EmbedAutomateExcel()
      {
         //Change the cursor so the user knows something exciting is going
         //on.
         BeginWaitCursor();

         CEmbed_ExcelCntrItem* pItem = NULL;
         TRY
         {
            //Get the document associated with this view, and be sure it's
            //valid.
            CEmbed_ExcelDoc* pDoc = GetDocument();
            ASSERT_VALID(pDoc);

            //Create a new item associated with this document, and be sure
            //it's valid.
            pItem = new CEmbed_ExcelCntrItem(pDoc);
            ASSERT_VALID(pItem);

            // Get Class ID for Excel sheet.
            // This is used in creation.
            CLSID clsid;
            if(FAILED(::CLSIDFromProgID(L"Excel.sheet",&clsid)))
               //Any exception will do. We just need to break out of the
               //TRY statement.
               AfxThrowMemoryException();

            // Create the Excel embedded item.
            if(!pItem->CreateNewItem(clsid))
               //Any exception will do. We just need to break out of the
               //TRY statement.
               AfxThrowMemoryException();

            //Make sure the new CContainerItem is valid.
            ASSERT_VALID(pItem);

            // Launch the server to edit the item.
            pItem->DoVerb(OLEIVERB_SHOW, this);

            // As an arbitrary user interface design, this sets the
            // selection to the last item inserted.
            m_pSelection = pItem;   // set selection to last inserted item
            pDoc->UpdateAllViews(NULL);

            //Query for the dispatch pointer for the embedded object. In
            //this case, this is the Excel worksheet.
            LPDISPATCH lpDisp;
            lpDisp = pItem->GetIDispatch();

            //Add text in cell A1 of the embedded Excel sheet
            _Workbook wb;
            Worksheets wsSet;
            _Worksheet ws;
            Range range;
            _Application app;

            //set _Workbook wb to use lpDisp, the IDispatch* of the
            //actual workbook.
            wb.AttachDispatch(lpDisp);

            //Then get the worksheet's application.
            app = wb.GetApplication();

            //Then get the first worksheet in the workbook
            wsSet = wb.GetWorksheets();
            ws = wsSet.GetItem(COleVariant((short)1));

            //From there, get a Range object corresponding to cell A1.
            range = ws.GetRange(COleVariant("A1"), COleVariant("A1"));

            //Fill A1 with the string "Hello, World!"
            range.SetValue(COleVariant("Hello, World!"));
         }

           //Here, we need to do clean up if something went wrong.
           CATCH(CException, e)
           {
              if (pItem != NULL)
              {
                 ASSERT_VALID(pItem);
                 pItem->Delete();
              }
              AfxMessageBox(IDP_FAILED_TO_CREATE);
           }
           END_CATCH

           //Set the cursor back to normal so the user knows exciting stuff
           //is no longer happening.
           EndWaitCursor();
        } 

将下面一行添加到 Embed_ExcelView.h:

      #include "excel8.h" 

注意:如果使用Excel 2000, 头文件是 "excel9.h."

看一下View类中的 OnInsertObject() 方法，对其中的注释引起了我们的兴趣，因为它和我们刚写的方法有惊人的相似。事实上，我们刚才写的是OnInsertObject()的一个特例：允许用户从可用的OLE对象列表中选择其一插入到应用程序中。因为我们只想对Excel工作表进行自动化，所以派生这一行为。在我们的程序中，我们移去了InsertObject()内部的所有代码然后把它称作EmbedAutomateExcel()。 

编译并运行我们的程序。 
在Edit 菜单中选择 Insert New Object. 

运行结果：一张Microsoft Excel 工作表插入到视图中；并且通过自动化，A1单元格被填上"Hello, World!" 字符串。