Accessing Excel fields from Visual C++ 3

[drexeliu]

The current project I am working on requires the ability to retrieve data from a Microsoft Excel file for use in the Visual C++ environment. Information is very sketchy about this sort of thing, but I do believe it is possible. It is definitely possible with Visual Basic, but this application requires C++. If anyone has any suggestions, either general or preferably specific, please let me know the steps necessary to accomplish this. Thanks!

 

[ggreg]

My Guess is its going to so kind of infile statements
like what was in my code problem. take a look at the code
that is in my question.

 

[TGM]

Hi

I include here some code I use to read Excel file
Use the Visual C++ on-line Help for details

HTH

Thierry
EMail: Thierry.Marneffe@swing.be
WebSite:

http://users.swing.be/TGMSoft

Here it is:

COleVariant covOptional(( long) DISP_E_PARAMNOTFOUND, VT_ERROR);
COleVariant covTrue(( short) TRUE);
COleVariant covFalse(( short) FALSE);

try
{
_Application app;
_Workbook book;
_Worksheet sheet;
Workbooks books;
Worksheets sheets;
Range range;

if ( !app.CreateDispatch( "Excel.Application&quot)
{
AfxMessageBox( Unable to Start Excel !!!"

return;
}

CWaitCursor wait;

// Get Workbooks Collection

books = app.GetWorkbooks();

// Open File

CString stre;

book = books.Open( strFile, covOptional, covTrue, covOptional, covOptional,
covOptional, covTrue, covOptional, covOptional, covFalse,
covOptional, covOptional, covFalse);

// Get Sheets

sheets = book.GetSheets();

// Get First Sheet

sheet = sheets.GetItem( COleVariant(( short) 1));

// Scan File to Get some Data

CMsg msg;
COleVariant covCell;
COleVariant covValue;
CTime t;
CString strUnit;
int nBatchNbr;
char szBuffer[100];

THIS is A SAMPLE ... DO as you NEED ...

for ( int nRow = 9; nRow <= 90; nRow += 2)
{
// Get Date

covCell = Cell( nRow, 3);

range = sheet.GetRange( covCell, covCell);

covValue = range.GetValue();

// Extract Date from COleVariant

if ( covValue.vt == VT_DATE)
{
t = GetOleVariant( covValue, t);
}
else
{
CString strMsg;

strMsg.Format( &quot;Error Getting Time Data (Row %d Col 3) !!!&quot;, nRow);

AfxMessageBox( strMsg);

// Avoid 'Save Changes' message

book.SetSaved( TRUE);

// Quit Excel

app.Quit();
}

// Scan Other Data

for ( int nCol = 4; nCol <= 27; nCol++)
{
// Get Unit Name

covCell = Cell( nRow, nCol);

range = sheet.GetRange( covCell, covCell);

covValue.Clear();

covValue = range.GetValue();

// Extract String ( with safety check)

if ( covValue.vt == VT_BSTR)
{

// Extract String
// Note: BSTRs are wide, double-byte (Unicode) strings on
// 32-bit Windows platforms

unsigned cmb = wcstombs( NULL, covValue.bstrVal,
SysStringLen( covValue.bstrVal)) + 1;

strnset( szBuffer, 100, ' ');

wcstombs( szBuffer, covValue.bstrVal, cmb);

strUnit.Format( &quot;%s&quot;, szBuffer);

}
}
}
// Avoid 'Save Changes' message

book.SetSaved( TRUE);

// Quit Excel

app.Quit();
}
catch( COleException *e)
{
char szBuffer[1024];

sprintf( szBuffer, &quot;COleException. SCODE: %08lx.&quot;, (long)e->m_sc);

m_EventLog.WriteLine( szBuffer);
}
catch( COleDispatchException *e)
{
char szBuffer[1024];

sprintf( szBuffer,
&quot;COleDispatchException. SCODE: %08lx, Description: \&quot;%s\&quot;.&quot;,
( long) e->m_wCode, ( LPSTR) e->m_strDescription.GetBuffer(1024));

m_EventLog.WriteLine( szBuffer);
}
catch(...)
{
m_EventLog.WriteLine( &quot;General Exception caught ...&quot;
}
}

 

[KeithBrautigam]

Here's a few links that might also be helpful.

Link #1: Microsoft Office Development with Visual Studio

http://msdn.microsoft.com/library/default.asp?URL=/library/techart/VSOfficeDev.htm

Link #2: Automating Microsoft Office 97 and Microsoft Office 2000

http://msdn.microsoft.com/library/default.asp?URL=/library/techart/offaut.htm

Also, CodeGuru has a brief sample that shows how to accomplish one simple task: printing a Word document. The general principles shown should apply to Excel as well.

http://codeguru.earthweb.com/interface/WordAutomation.html