Opening Excel files from C#

Question

I have an issue when working with Excel from C# using the Microsoft.Office.Interop.Excel object.

The problem comes when I try and open a file to write to that I have already have open in Excel. This ultimately errors and then leaves an instance of Excel running in the background.

How can I tell that the file is already open before opening it?

Also what is the convention for disposing with the Excel objects and therefore killing the Excel process?

score 2 · Accepted Answer · edited May 23 '17 at 11:48

2

The following article provides a good way of checking if a file is open already:

Is there a way to check if a file is in use?

This article talks about killing the excel process:

Kill Process Excel C#

Hope these are helpful

edited May 23 '17 at 11:48

Community

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answered Jul 25 '12 at 11:43

Gaz Winter

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score 0 · Answer 2 · answered Jul 25 '12 at 11:53

Hello you must to dispose your excel objects at end of treatment (workbook, applicationClass, usedRange, worksheet)

        workbook.Close(false, workbookPath, null);
        applicationClass.Quit();

        while (Marshal.ReleaseComObject(usedRange) > 0)
        { }
        while (Marshal.ReleaseComObject(worksheet) > 0)
        { }
        while (Marshal.ReleaseComObject(workbook) > 0)
        { }
        while (Marshal.ReleaseComObject(applicationClass) > 0)
        { }

score 0 · Answer 3 · answered Jun 23 '14 at 08:43

For opening of already opened - for more just type Workbooks.Open on the MSDN. Here is the save sample, you just overwrite (an still opened) without querying :o), xlShared and xlLocalSessionChanges are keywords.

            _xlsWorkbook.SaveAs(
                 targetFileName                                                     /* Filename */
                ,Excel_ForMissing.XlFileFormat.xlExcel8                             /* FileFormat */
                ,Missing.Value                                                      /* Password */
                ,Missing.Value                                                      /* WriteResPassword */
                ,Missing.Value                                                      /* ReadOnlyRecommended */
                ,Missing.Value                                                      /* CreateBackup */
                ,Excel_ForMissing.XlSaveAsAccessMode.xlShared                       /* AccessMode */
                ,Excel_ForMissing.XlSaveConflictResolution.xlLocalSessionChanges    /* ConflictResolution */
                ,false                                                       /* AddToMru */
                ,Missing.Value                                                       /* TextCodepage */
                ,Missing.Value                                                       /* TextVisualLayout */
                ,true                                                       /* Local */
            );

Opening Excel files from C#

3 Answers3