How To Automate Excel to Create And Format a New Workbook Using C++ .NET and MFC

This article demonstrates how to create an Automation client for Excel by using Microsoft Foundation Classes (MFC) and Visual C++ .NET.

Automation is a process that allows applications that are written in languages such as MFC to programmatically control other applications. Automation to Excel allows you to perform actions such as creating a new workbook, adding data to the workbook, or creating charts. With Excel and other Microsoft Office applications, virtually all of the actions that you can perform manually through the user interface can also be performed programmatically by using Automation.

Excel exposes this programmatic functionality through an object model. The object model is a collection of classes and methods that serve as counterparts to the logical components of Excel. For example, there is an Application object, a Workbook object, and a Worksheet object, each of which contain the functionality of those pieces of Excel. To access the object model from MFC and Visual C++ .NET, you can create an MFC wrapper class from Excel's type library.

This article demonstrates how to use the wrapper classes that are generated by MFC to create and format a new workbook by using Visual C++ .NET.

Create an Automation Client for Microsoft Excel

1. Follow the steps in the "Create an Automation Client" section of the following Microsoft Knowledge Base article to create a basic Automation client:
   307473

   (http://support.microsoft.com/kb/307473/EN-US/ )

   How To Use a Type Library for Office Automation from Visual C++ .NET
   In step 4d of the article, select the following interfaces:
   
   
   • _Application
   • Workbooks
   • _Workbook
   • Worksheets
   • _Worksheet
   • Range
   • Font
   • Interior
   • Borders
   • Border
   
   In step 6 of the article (where you add #include statements for each of the classes for which you generated wrappers), note that the file for the Font class is CFont0.h and the file for the Interior class is Cnterior.h.
2. In the IDD_AUTOPROJECT_DIALOG dialog box, right-click Run and select Add event handler. In the Event Handler Wizard, select the BN_CLICKED message type and then click Add and Edit. Add the following code in the handler for automating Excel:

   void CAutoProjectDlg::OnBnClickedRun()
   {
      // Commonly used OLE variants.
      COleVariant
         covTrue((short)TRUE),
         covFalse((short)FALSE),
         covOptional((long)DISP_E_PARAMNOTFOUND, VT_ERROR);
   
      CApplication app;
      CWorkbooks books;
      CWorkbook book;
      CWorksheets sheets;
      CWorksheet sheet;
      CRange range;
      CFont0 font;
      CRange cols;
      CRange resizedrange;
      Cnterior interior;
      CBorders borders;
      CBorder bottomborder;
   
      // Start Excel and get an Application object.
      if(!app.CreateDispatch("Excel.Application"))
      {
         AfxMessageBox("Couldn't start Excel and get Application object.");
         return;
      }
   
      //Get a new workbook.
      books = app.get_Workbooks();
      book = books.Add (covOptional);
   
      //Get the first sheet.
      sheets =book.get_Sheets();
      sheet = sheets.get_Item(COleVariant((short)1));
   
      //Fill cells A1, B1, C1, and D1 one cell at a time with "headers".
      range = sheet.get_Range(COleVariant("A1"),COleVariant("A1"));
      range.put_Value2(COleVariant("First Name"));
      range = sheet.get_Range(COleVariant("B1"),COleVariant("B1"));
      range.put_Value2(COleVariant("Last Name"));
      range = sheet.get_Range(COleVariant("C1"),COleVariant("C1"));
      range.put_Value2(COleVariant("Full Name"));
      range = sheet.get_Range(COleVariant("D1"),COleVariant("D1"));
      range.put_Value2(COleVariant("Salary"));
   
      //Format A1:D1 as bold, vertical alignment = center.
      range = sheet.get_Range(COleVariant("A1"), COleVariant("D1"));
      font = range.get_Font();
      font.put_Bold(covTrue);
      range.put_VerticalAlignment(
         COleVariant((short)-4108));   //xlVAlignCenter = -4108
   
      //Fill A2:B6 with an array of values (First & Last Names).
      {
         COleSafeArray saRet;
         DWORD numElements[]={5,2};   //5x2 element array
         saRet.Create(VT_BSTR, 2, numElements);
   
   
         //Fill the 5x2 SafeArray with the following data:
         //   John      Smith
         //   Tom       Brown
         //   Sue       Thomas
         //   Jane      Jones
         //   Adam      Johnson
   
         FillSafeArray(L"John", 0, 0, &saRet);
         FillSafeArray(L"Smith", 0, 1, &saRet);
         FillSafeArray(L"Tom", 1, 0, &saRet);
         FillSafeArray(L"Brown", 1, 1, &saRet);
         FillSafeArray(L"Sue", 2, 0, &saRet);
         FillSafeArray(L"Thomas", 2, 1, &saRet);
   
         FillSafeArray(L"Jane", 3, 0, &saRet);
         FillSafeArray(L"Jones", 3, 1, &saRet);
         FillSafeArray(L"Adam", 4, 0, &saRet);
         FillSafeArray(L"Johnson", 4, 1, &saRet);
   
         range = sheet.get_Range(COleVariant("A2"), COleVariant("B6"));
         range.put_Value2(COleVariant(saRet));
   
         saRet.Detach();
      }
   
      //Fill C2:C6 with a relative formula (=A2 & " " & B2).
      range = sheet.get_Range(COleVariant("C2"), COleVariant("C6"));
      range.put_Formula(COleVariant("=A2 & \" \" & B2"));
   
      //Fill D2:D6 with a formula(=RAND()*100000) and apply a number
      //format.
      range = sheet.get_Range(COleVariant("D2"), COleVariant("D6"));
      range.put_Formula(COleVariant("=RAND()*100000"));
      range.put_NumberFormat(COleVariant("$0.00"));
   
      //AutoFit columns A:D.
      range = sheet.get_Range(COleVariant("A1"), COleVariant("D1"));
      cols = range.get_EntireColumn();
      cols.AutoFit();
   
      //Manipulate a variable number of columns for Quarterly Sales Data.
      {
         short NumQtrs;
         CString msg;
   
         //Determine how many quarters to display data for.
         for(NumQtrs=1;NumQtrs<=3;NumQtrs++)
         {
            msg.Format("Enter sales data for %d quarter(s)?", NumQtrs);
            if(AfxMessageBox(msg,MB_YESNO)==IDYES)
            {
               break;
            }
         }
         msg.Format("Displaying data for %d quarters.", NumQtrs);
         AfxMessageBox(msg);
   
         //Starting at E1, fill headers for the number of columns selected.
         range = sheet.get_Range(COleVariant("E1"), COleVariant("E1"));
         resizedrange = range.get_Resize(covOptional, COleVariant(NumQtrs));
         resizedrange.put_Formula(
            COleVariant("=\"Q\" & COLUMN()-4 & CHAR(10) & \"Sales\""));
         //Change the Orientation and WrapText properties for the headers.
         resizedrange.put_Orientation(COleVariant((short)38));
         resizedrange.put_WrapText(covTrue);
         //Fill the interior color of the headers.
         interior = resizedrange.get_Interior();
         interior.put_ColorIndex(COleVariant((short)36));
   
         //Fill the columns with a formula and apply a number format.
         range = sheet.get_Range(COleVariant("E2"), COleVariant("E6"));
         resizedrange = range.get_Resize(covOptional, COleVariant(NumQtrs));
         resizedrange.put_Formula(COleVariant("=RAND()*100"));
         resizedrange.put_NumberFormat(COleVariant("$0.00"));
   
         //Apply borders to the Sales data and headers.
         range = sheet.get_Range(COleVariant("E1"), COleVariant("E6"));
         resizedrange= range.get_Resize(covOptional, COleVariant(NumQtrs));
         borders = resizedrange.get_Borders();
         borders.put_Weight(COleVariant((short)2));   //xlThin = 2
   
         //Add a Totals formula for the Quarterly sales data and apply a
         //border.
         range = sheet.get_Range(COleVariant("E8"), COleVariant("E8"));
         resizedrange = range.get_Resize(covOptional, COleVariant(NumQtrs));
         resizedrange.put_Formula(COleVariant("=SUM(E2:E6)"));
         borders = resizedrange.get_Borders();
         {
            bottomborder = borders.get_Item((long)9);
            bottomborder.put_LineStyle(
               COleVariant((short)-4119));   //xlDouble = -4119
            bottomborder.put_Weight(
               COleVariant((short)4));       //xlThick = 4
         }
      }
   
      //Make the application visible and give the user control of
      //Excel.
      app.put_Visible(TRUE);
      app.put_UserControl(TRUE);
   }
   					

3. Add the following code immediately above the OnBnClickedRun method. This code simplifies creating an array that is used to send data to Excel:

   void FillSafeArray(OLECHAR FAR* sz, int iRow, int iCol,
                      COleSafeArray* sa)
   {
   
      VARIANT v;
      long index[2];
   
      index[0] = iRow;
      index[1] = iCol;
   
      VariantInit(&v);
      v.vt = VT_BSTR;
      v.bstrVal = SysAllocString(sz);
      sa->PutElement(index, v.bstrVal);
      SysFreeString(v.bstrVal);
      VariantClear(&v);
   
   }
   					

4. Press F5 to build and run the Automation client.
5. When the dialog box appears, click Run.
   
   The Automation client starts Excel and creates a sample workbook. Excel remains running even when the Automation client ends because the user has been given control of the application.

For additional information on automating Excel by using MFC and Visual C++ .NET, click the article number below to view the article in the Microsoft Knowledge Base: