How can I mannually terminate an excel application using OLE Automation?
I would like to do this in some exception handling so that an excel process does not remain running if a function throws an error.
Currently I use the below code to open excel:
Variant excel = Variant::CreateObject("Excel.Application");
Like this:
OleVariant excel;
excel = Variant::CreateObject("Excel.Application");
//
// Your code
//
excel.OleProcedure("Quit");
Related
I'm working on Visual Studio 2019 community, and I'm writing an MFC application in cpp. I want to add a functionality to the dialog box - such that when pressing a button it converts an existing xls file into pdf file. I've tried using the extension Aspose.Cells.Cpp and Aspose.PDF.Cpp with this code, but I get a lot of errors in the code of the DLL itself. I've also tried installing libHARU from here, but I didn't manage to make it work.
I've tried looking for another way to convert xls to pdf in MFC application in cpp, or another environment for creating desktop applications (which has some basic functionalities such as adding a pressing button in MFC, so I won't have to write everything from scratch with Win32 API), but I didn't find anything. Perhaps someone can explain to me how to perform this conversion in cpp so that I can use it when writing an MFC app, or could refer me to some useful information about another way of creating the application which supports this type of conversions?
You said in your comments to me that you can assume the user has Excel installed on his machine. If so, then you can use Excel's automation object model to manipulate Excel. You could do stuff like #import the type library and stuff...maybe that would make prettier C++. My experience, however, with driving Office apps is to stick more with just raw dispatch pointers. I've had less go wrong that way. This probably needs some more error checking and stuff, but that's up to you.
... and a big caveat. This is for an interactive app...which I halfway assume since you are using the MFC topic. With a service, Microsoft does not recommend you drive their Office applications in this manner. I tested this on one .xlsx file and it worked. Assume it will work for .xls as well. For other formats, you might need to use different import functions.
void ConvertFile(LPCWSTR lpszFileIn, LPCWSTR lpszFileOut)
{
CComDispatchDriver excel;
if (SUCCEEDED(excel.CoCreateInstance(_T("Excel.Application"), NULL, CLSCTX_LOCAL_SERVER)))
{
_variant_t vWorkbooks;
if (SUCCEEDED(excel.GetPropertyByName(L"Workbooks", &vWorkbooks)))
{
CComDispatchDriver workbooks(vWorkbooks.pdispVal);
_variant_t vWorksheet;
if (SUCCEEDED(workbooks.Invoke1(L"Open", &_variant_t(lpszFileIn), &vWorksheet)))
{
CComDispatchDriver worksheet(vWorksheet.pdispVal);
UINT xlTypePdf = 0;
HRESULT hr = worksheet.Invoke2(L"ExportAsFixedFOrmat", &_variant_t(xlTypePdf), &_variant_t(lpszFileOut), NULL);
if (FAILED(hr))
{
_com_error err(hr);
AfxMessageBox(err.ErrorMessage());
}
}
}
excel.Invoke0(L"Quit", NULL);
}
}
I'll give a solution, but this one doesn't use c++, just command line and LibreOffice app:
Use command line Libre Office tool: --convert-to
--convert-to output_file_extension[:output_filter_name] [--outdir output_dir] files
Batch convert files. If --outdir is not specified, then current working directory is used as output_dir.
Eg. --convert-to pdf *.doc
--convert-to pdf:writer_pdf_Export --outdir /home/user *.doc
More details about how to use this command you'll find here: https://help.libreoffice.org/Common/Starting_the_Software_With_Parameters
Later edit: Here is a sample of how to implement the above solution in a C++/MFC code:
STARTUPINFO si = { 0 };
si.cb = sizeof(si);
PROCESS_INFORMATION pi = { 0 };
sCommand.Format(_T("C:\\WINDOWS\\System32\\cmd.exe /c
C:\\LibreOffice\\program\\swriter.exe --convert-to pdf -outdir
c:\\temp\\ c:\\temp\\MyFile.doc"));
::CreateProcess(0, sCommand, 0, 0, TRUE, CREATE_NO_WINDOW, 0, 0, &si, &pi);
I am new to C++ (was previously into Java) and I am trying to find my way around it for the past few days. I am having a Sqlite DB in my local Machine which I am trying to access in order to display the results of a query on a Windows Application Form using DataGridView.
I was able to locate a good place to start here but later discovered that this was more concentrated towards SQL server and not SQLite and the code failed when I tried to replace this part of code
String^ connectionString =
"Integrated Security=SSPI;Persist Security Info=False;" +
"Initial Catalog=Northwind;Data Source=localhost";
with this
String^ connectionString = "Data Source=C:\\data\\test.db"
to point to my local Sqlite DB (test.db).
Upon more digging I found that I was able to find C# examples for linking SQLite DB to Windows Form Application here. Next I tried to convert the C# code provided into a C++ one but failed.
I have been looking all around for simple C++ examples which would help me understand how to link a Sqlite DB to a Windows Form Application but am not able to do so yet.
I would appreciate it greatly if anyone could point me to one such example.
To access SQLite DB from managed code use System.Data.SQLite library. It's a managed library supported by SQLite Development Team and you can use it with managed C++ also. Here is the sample:
using namespace System::Data::SQLite;
using namespace System::Text;
void Test()
{
SQLiteConnection ^db = gcnew SQLiteConnection();
try
{
db->ConnectionString = "Data Source=C:\\data\\test.db";
db->Open();
// Do the job here
db->Close();
}
finally
{
delete (IDisposable^)db;
}
}
I am working on one MFC Application where I have to use sqlite database of iOS application.
The iOS database is encrypted by using SQLite API called sqlite3_key().
But when I am trying to open the same database of iOS in my MFC Application it throws exception saying File is encrypted or not a database and unable to read the data from the database.
The iOS database will be downloaded from Dropbox by MFC application and will replace current database and use it instead of previous
I am using following code for opening the database using CppSqlite3 Wrapper for Sqlite:
CppSQLite3DB db;
try{
db.open("mydb.db");
TRACE(_T("database opened"));
db.key("1234", strlen("1234"));
}catch(CppSQLite3Exception e){
return NULL;
}
As the CppSQLite3DB class does not have a function called key(). I have added that function in the class
void CppSQLite3DB::key(const char* szKey, int nKey)
{
if (mpDB)
{
sqlite3_key(mpDB, szKey, nKey);
}
}
and upgrade my library to SQLiteEncrypt.
Whereas The iOS application is using SQLCipher for Database.
But, the result is same. So,
Can anyone tell me how I can achieve that?
Thank you in Advance.
From http://sqlcipher.net/:
SQLCipher has broad platform support for [..] C/C++ [..] iPhone/iOS [..]
Perhaps using SQLCipher in your Windows application would solve incompatibility problems.
I want to develop a small tool which for open XML file and launch Excel automatically.
The benefit for user who could save the excel file to .xls format very conveniently.
My Dev IDE: Windows XP pro & Visual Studio 2005.
The tool will running at Windows 2000 & Excel 2000. and there is no .net framework installed.
That means i can't code with C#. My choice is C++.
Oneliner:
int main() {
system("Start Excel test.xml");
}
If I recall correctly you want to open an excel file and then auto launch xml editor?
A way is to add a option the the contect menu when rightclicking on the xls file.
Use register for this:
HKEY_CLASSES_ROOT.xls\shell\
create a key (Default) and value something like "Open excel and xml editor"
create a folder "command" and a key (Default) with value "path to your exe" "%L" in that folder.
Then in your app catch the param (which holds the xls)
and then do something like this:
system(<var holding the xls name>);
system(<path to xml editor>):
You could use ShellExecute. It will automatically start program which associated with certain extension, or you could select program manually.
In C#
OpenXML in MSDN - http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel.workbooks.openxml(v=office.11).aspx
using Excel = Microsoft.Office.Interop.Excel;
string workbookPath= #"C:\temp\Results_2013Apr02_110133_6692.xml";
this.lblResultFile.Text = string.Format(#" File:{0}",workbookPath);
if (File.Exists(workbookPath))
{
Excel.Application excelApp = new Excel.Application();
excelApp.Visible = true;
Excel.Workbook excelWorkbook = excelApp.Workbooks.OpenXML(workbookPath, Type.Missing, Excel.XlXmlLoadOption.xlXmlLoadPromptUser);
}
else
{
MessageBox.Show(String.Format("File:{0} does not exists", workbookPath));
}
I am writing an background service application that has to automatically read data from Excel 2003 files. But no matter what I try, the method OlePropertyGet() always results in an EAccessViolation error while trying to read from address "00000800".
The error always occurs at the last line of this code snippet, and seems independent of what parameter the method receives:
Variant excel, workbooks;
try
{
excel = GetActiveOleObject("Excel.Application");
}
catch(...)
{
excel = CreateOleObject("Excel.Application");
}
workbooks = excel.OlePropertyGet("Workbooks");
I've done some extensive google search on this, but found nothing that's even remotely helpful, only this forum thread where someone has the same issue, but doesn't give any information about the cause or solution (it's somewhat funny that at one point the author mentions he knows the cause, but doesn't say what it is!).
I'm open to any ideas as to what is causing this and how to solve this problem, but also alternative approaches to Excel OLE automation.
My guess is its a null pointer issue..
It looks like neither GetActiveOleObject() nor CreateOleObject() worked.
Try checkign the validity of 'excel' before calling OlePropertyGet.
And I guess you should make sure you have Excel installed.
You can use Visual Studio Tools for Office (see http://msdn.microsoft.com/en-us/library/d2tx7z6d.aspx).
Or you can use ATL support to instantiate the object model provided by office.
Your code may not be able to resolve "Excel.Application" successfully, leading to a null pointer. It uses a registry lookup with that string to identify Excel. It sounds like you're missing that registry entry.
I use such code to determine validity of created objects(in C++ Builder):
Varaint excel = GetActiveOleObject("Excel.Application");
TAutoDriver<IDispatch> dispatcher;
dispatcher.Bind(excel, false);
if (dispatcher.IsBound())
{
Variant workbooks = excel.OlePropertyGet("Workbooks");
}