C# - Kill EXCEL.exe process referencing a particular file

Question

I have a C# application that creates an excel file. But if the file is left open and the app is run the second time, it throws IO exception (since, in the code I am replacing the existing file with new one) Now, I want to check if the file is open and kill the excel.exe process that is referencing this file. Is there any way this can be achieved?

Note: There might be several excel files open. I want to close only the process that is using my file.

xlFilePath = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
File.Copy(xlFilePath + "\\file.xlsx", String.Format("{0}\\OutputFile{1}.{2}.xlsx", xlFilePath, DateTime.Now.Year, DateTime.Now.Month), true);
xlFilePath = Path.Combine(xlFilePath, String.Format("{0}\\OutputFile{1}.{2}.xlsx", xlFilePath, DateTime.Now.Year, DateTime.Now.Month));

appl = new Excel.Application(Visible = false);
wbookss = appl.Workbooks;
wbook = wbookss.Open(xlFilePath);
//Excel.Worksheets wsheetss = appl.Worksheets;
wsheet = wbook.Sheets["Sheet1"];

Application_GenerateReport(wsheet);
Clipboard.Clear();
wbook.Close(true);
wbookss.Close();
appl.Quit();

System.Runtime.InteropServices.Marshal.ReleaseComObject(wsheet);
System.Runtime.InteropServices.Marshal.ReleaseComObject(wbook);
System.Runtime.InteropServices.Marshal.ReleaseComObject(wbookss);
System.Runtime.InteropServices.Marshal.ReleaseComObject(appl);

EDIT: The file remains open if there was an exception in the last run. If it is opened by a user, it can be killed by checking the MainWindowTitle property (As suggested by Yeldar).

I would say, that I think you are approaching the problem from the wrong end. Your program should gracefully handle this exception. Perhaps with a possible retry? That's much nicer than attempting to send Excel to oblivion (taking any potential user changes with it). Plus Office tends to nag you with _"a problem occurred opening this file before, open it again?"_ or some such — , Nov 27 '15 at 05:57
^The report is generated only using this app, never modified manually. — SharpCoder, Nov 27 '15 at 06:01
[This post](http://stackoverflow.com/questions/13807102/find-all-open-excel-workbooks) describes how you can get that running excel instance. You should consider that instance instead of killing it — Oguz Ozgul, Nov 27 '15 at 06:06

Tony Wu · Answer 1 · 2015-11-27T08:00:38.367

1

Another solution could be:

System.Diagnostics.Process.Start("CMD.exe","taskkill /f /im excel.exe");

This line will call command prompt and running the command taskkill.

All opening excel programs will be killed in this way.

Updated: (For one file)

System.Diagnostics.Process.Start("CMD.exe","taskkill /FI "WindowTitle eq Microsoft Excel - filename.xls");

edited Nov 27 '15 at 08:00

answered Nov 27 '15 at 06:20

Tony Wu

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Yeldar Kurmangaliyev · Accepted Answer · 2015-11-27T06:09:16.513

As Excel stores the name of the opened file in its title like this:

Microsoft Excel - filename.xls

You can iterate through the processes and kill the one with the given name:

string filename = "mylist.xls";
var excelProcesses = Process.GetProcessesByName("excel");

foreach (var process in excelProcesses)
{
  if (process.MainWindowTitle == $"Microsoft Excel - {filename}") // String.Format for pre-C# 6.0 
  {
     process.Kill();
  }
}

Note that:

it will also close all opened files with the same name
it will abandon any changes that user could change
title of Excel window may (or not, not sure, need to check) vary from version to version

However, as I said in comments, it is better to fix causes, but not consequences - just make your program start new Excel application without errors.

C# - Kill EXCEL.exe process referencing a particular file

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