I have a process that builds an Excel report, then opens it for the user. The problem is if someone leaves the file open, it stays locked and nobody else can build the report until the first person exits the excel file.
Is there a way to open an Excel file without locking it, using either Process.Start or Microsoft's Interop.Excel library?
I use the Interop library to build the file each time the report is run, and save it as a static file name in a shared network folder where this application is run from
using Excel = Microsoft.Office.Interop.Excel;
...
xlsBook.SaveAs(newFileName, Excel.XlFileFormat.xlWorkbookNormal);
And open the file using Process.Start
Process.Start(newFileName);
You can try to open the file in read-only mode:
var app = new Microsoft.Office.Interop.Excel.Application();
var workbook = app.Workbooks.Open(filename, ReadOnly: true);
Or you can try to save it in shared mode:
workbook.SaveAs(filename, AccessMode: XlSaveAsAccessMode.xlShared);
If the end user only has to read the file instead of also modifying it, you could create a shadow copy and then open that copy.
Simply copy the original file to a temporary location and open it from there. The original file remains untouched and can thus be opened by others.
Related
My program uses office interop by starting an Excel application (process) and opening an existing workbook.
I must be absolutely certain that all changes written to the workbook by the program can be saved, i.e. something similar to opening a System.IO.File with FileShare.Read or FileShare.None
If file is already opened for writing, my program must be able to detect that.
Anyone knows how to do?
You may check readonly or isDirty.
With a sample program this may be checked quickly by opening the same workbook in Excel at the same time.
I have a doubt about the excel sheet. When I apply the formula column. If my code throws any exceptions/errors then my excel file is set as a read-only mode. So, here I want my file remains in read-write mode. Please, help me to solve this problem.
There are multiple reasons why the file may only be available in read-only mode:
Someone other process is using the file. Perhaps one of your earlier Excel instances you left opened after a crash / exception? Utilize Task Manager to kill ghost instances of Excel or other apps that may be using the file.
The file is opened in read only mode. Here's some info on how to open it in editable mode. https://www.stellarinfo.com/article/excel-cannot-open-read-only-document.php
I have a Visual Studio solution that contains two projects (1) a C# console application; and (2) a C# Excel Workbook.
The console application creates some data, which I would then like to pass into the workbook.
To do this I have created a method in the Excel workbook project, which receives data from the console application. However, I cannot create an instance of the Excel book. At the moment I am trying:
Excel.Application excelApplication = new Excel.Application();
Excel.Workbook excelWorkBook = excelApplication.Workbooks.Add("MyBook.xls");
I could hard code the path to the xls file, but I don't really want to do this as I would prefer to wrap everything up into a single .exe
Any ideas?
So basically what you're asking is how to wrap two files (an exe and an excel file), into a single exe.
There is a simple (and fairly clumsy) way of doing this which revolves around using Resources in C#, meaning your program will have to do something similar to the following:
Take excel file source out of Resources, and write it to a file when the program is run (temporary file)
Use the Current Directory + excel temp file name to feed into the Worksheet.Add method
Once edited, store the temporary file's data back into the Resources of your exe.
Another possibility would be, instead of using a temporary file, read a stream of bytes directly into Worksheets.Add if this is supported by the API (feel free to tell me if this is so).
EDIT: Great tutorial on using resources in C#.
I am writing to the text file some data. I am using this code:
using (FileStream fs = new FileStream(path, FileMode.Append, FileAccess.Write, FileShare.ReadWrite))
{
using (TextWriter tw = new StreamWriter(fs))
{
tw.WriteLine("sample_data");
}
}
When file is opened by notepad my app can write into it. When this file is opened by MS Excel I get following error: The process cannot access the file myfile.csv because it is being used by another process. What can cause this situation and how can I solve this problem?
Notepad opens the file, reads in the entire contents and then closes the file. You can even delete the file that is open in notepad.
Excel on the other hand keeps the file open as long as it is displayed. There are some special sharing tools that can be enabled in Excel for excel format files. In that case I assume that it is opened non-exlusively. Otherwise Excel opens the file exclusively and keeps it open.
It doesn't matter that you specify a share option when opening, if the file is already opened by someone else in exclusive mode.
Excel will lock the file when it is open which prevents interaction with the file. One way I worked around this is that I wrote code to scan for excel processes on the local machine and would kill those processes before accessing a file that was open with excel. You could determine if a file is locked by looking at How to check for file lock? and then running the process killing code in the exception handler.
Open the csv file using OleDB and use INSERT and/or UPDATE statements.
I have UI tests. When the UI tests finish, they open the result files in an Excel document (Excel 2007 is installed on the test environment) - but the problem is that the excel document is not saved anywhere on the computer. They exist only when the AutoRecover feature saves the temporary files as a .xar file, so this is useless to us.
We use a C# .NET program to launch the UI tests (and do a bunch of other things), so I'm looking to see if it's possible to save this OPENED excel document programmatically.
Is that possible?
Thanks
This may help you How to: Save Workbooks
Example
This example creates a new workbook, prompts the user for a file name, and then saves the workbook.
Set NewBook = Workbooks.Add
Do
fName = Application.GetSaveAsFilename
Loop Until fName <> False
NewBook.SaveAs Filename:=fName