Getting excel application process id

Question

I am creating an excel application with c#. Since I will maintain the excel file in urgency I want to keep its handler open. I want to keep the excel process id so I will be able to kill it in case the system crashs.

How can I get the Excel Pid when creating it?

can you start telling us how you create/open excel? show some code please — Davide Piras
– Davide Piras, Commented Dec 13, 2011 at 14:10
What do you need the PID for? you can release the Com objects yourself — Shai
– Shai, Commented Dec 13, 2011 at 14:10

Nick Spreitzer · Accepted Answer · 2013-03-21 19:56:11Z

48

using Excel = Microsoft.Office.Interop.Excel;
using System.Runtime.InteropServices;
using System.Diagnostics;

class Sample
{
    [DllImport("user32.dll")]
    static extern int GetWindowThreadProcessId(int hWnd, out int lpdwProcessId);

    Process GetExcelProcess(Excel.Application excelApp)
    {
        int id;
        GetWindowThreadProcessId(excelApp.Hwnd, out id);
        return Process.GetProcessById(id);
    }
}

answered Mar 21, 2013 at 19:56

Nick Spreitzer

10.6k5 gold badges41 silver badges59 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Shai · Accepted Answer · 2011-12-13 14:14:10Z

-1

Here's an example of how to open an Excel file using Excel-Interop, and properly disposing the instance (source: google)

    Application ExcelObj = new Application();
    Workbook WB = ExcelObj.Workbooks.Open(fileName,
        0, true, 5, "", "", true, XlPlatform.xlWindows, "\t",
        false, false, 0, true, false, false);
    Sheets sheets = WB.Worksheets;
    Worksheet WS = (Worksheet)sheets.get_Item(1);
    Range excelRange = WS.UsedRange;

        ... (DO STUFF?)

        // Get rid of everything - close Excel
        while (Marshal.ReleaseComObject(WB) > 0) { }
        WB = null;
        while (Marshal.ReleaseComObject(sheets) > 0) { }
        sheets = null;
        while (Marshal.ReleaseComObject(WS) > 0) { }
        WS = null;
        while (Marshal.ReleaseComObject(excelRange) > 0) { }
        excelRange = null;
        GC();
        ExcelObj.Quit();
        while (Marshal.ReleaseComObject(ExcelObj) > 0) { }
        ExcelObj = null;
        GC();

    public static void GC()
    {
        System.GC.Collect();
        System.GC.WaitForPendingFinalizers();
        System.GC.Collect();
        System.GC.WaitForPendingFinalizers();
    }

answered Dec 13, 2011 at 14:14

Shai

25.7k9 gold badges48 silver badges69 bronze badges

4 Comments

Noah Yetter Over a year ago

Probably downvoted because it doesn't answer the question! If Excel goes out to lunch, which it often does, releasing all your references to it is not going to kill it. You NEED the process id.

Noah Yetter Over a year ago

Yes, you do. Excel processes started through COM are not child processes of your process, they are children of svchost.exe. If Excel is performing a blocking operation such as QueryTable.Refresh(), and your process exits, excel.exe will not die. If you're doing those refreshes in threads or subprocesses, which you might need to terminate, you're doomed to accumulate zombie excel processes, UNLESS you can track their process id's and kill them.

Shai Over a year ago

@NoahYetter I've been working with Excel through COM for the past 3 years and have never had problems with zombie processes using this code.

Noah Yetter Over a year ago

Have you ever used QueryTable.Refresh()? Seriously, try it. Create a thread or subprocess, launch excel, load a workbook, start a long-running Refresh(), then terminate your thread/process. Instant zombie excel.

Collectives™ on Stack Overflow

Getting excel application process id

2 Answers 2

Comments

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related