unable to open excel file from c# application

Question

I am trying to open an excel file through open file dialog but I am getting the following error

enter image description here

this the code i'v written, lemme know where it goes wrong

Excel.Application excelApp = new Excel.Application();
Excel.Workbook newWorkbook = excelApp.Workbooks.Add();  
Excel.Workbook excelWorkbook = null;
OpenFileDialog ofd = new OpenFileDialog();
ofd.Filter = "Excel Files |*.xlsx";
ofd.InitialDirectory = @"C:\";
if (ofd.ShowDialog() == DialogResult.OK)
{
    string path = System.IO.Path.GetFullPath(ofd.FileName);
    try
    {
        excelWorkbook = excelApp.Workbooks.Open(path,
        0, false, 5, "", "", false, Excel.XlPlatform.xlWindows, "",
        true, false, 0, true, false, false);
    }
    catch (Exception theException)
    {
        String errorMessage;
        errorMessage = "Error: ";
        errorMessage = String.Concat(errorMessage, theException.Message);
        errorMessage = String.Concat(errorMessage, " Line: ");
        errorMessage = String.Concat(errorMessage, theException.Source);
        MessageBox.Show(errorMessage, "Error");
    }
}

I am doing this coz I need to get values from the excel sheet. Please let me know if you require more details.

Edit -: when I looked closely I understood that the message box is not prompted for the first trial of opening the file, but the file does not open and then the message box appears during every successive trial of opening it. As suggested by @Pankaj, I tried adding Finally at the bottom but I still get the message box after 2nd trial of opening the file.

Do you have by any chance that same file already opened in Excel? — veljkoz
– veljkoz, Commented Sep 3, 2013 at 11:57
While not solving the current problem I thought I'd give a tip about closedxml.codeplex.com which I've always found easier then to actually work with Excel. — Don
– Don, Commented Sep 3, 2013 at 12:56

vin · Accepted Answer · 2013-09-11 10:24:17Z

1

Well, a missing line in the code was -: excelApp.Visible = true;

the code now looks like-:

excelWorkbook = excelApp.Workbooks.Open(path,
            0, false, 5, "", "", false, Excel.XlPlatform.xlWindows, "",
            true, false, 0, true, false, false);
// do the operations on file
.
.
// open the file here 
excelApp.Visible = true;

As suggested by @Pankaj, I applied

finally
{
    excelWorkbook.Close();
    excelApp.Application.Quit();
    Marshal.ReleaseComObject(excelApp);
}

but the problem with this is that the file closes immediately as we close workbook and excel application and I do not want the file to close as I would perform operations and user would then view the excel file. Also, closing application and workbook throws an unhandeled NullReferenceException if the user does not choose any file and closes the file dialogue. So I improved the the block and it now looks like

finally
{
    Marshal.ReleaseComObject(excelApp);
}

There is just one catch though, a new file along with the selected file is opened, its not a problem as of now but I am working on closing the newly opened file. thank you for your answeres @pankaj and @Csaba. :)

edited Sep 11, 2013 at 10:24

answered Sep 4, 2013 at 4:57

vin

8794 gold badges17 silver badges33 bronze badges

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

2 Comments

Pankaj Over a year ago

@Vim, If you think my answer was useful, Please upvote our answers, that is StackOverflow method of saying Thanks. :)

vin Over a year ago

@Pankaj Yes, if I think your answer is useful I will surely do that! :) and that would even be my method of saying thanks.. ;)

Pankaj · Accepted Answer · 2013-09-03 12:53:20Z

0

You should close your file and quit excel once you are done with that, so Add this finally thing in the end of your code

try
{
    excelWorkbook = excelApp.Workbooks.Open(path,
    0, false, 5, "", "", false, Excel.XlPlatform.xlWindows, "",
    true, false, 0, true, false, false);
    // ... Do all your processing with excel file here
}
catch (Exception theException)
{
    String errorMessage;
    errorMessage = "Error: ";
    errorMessage = String.Concat(errorMessage, theException.Message);
    errorMessage = String.Concat(errorMessage, " Line: ");
    errorMessage = String.Concat(errorMessage, theException.Source);
    MessageBox.Show(errorMessage, "Error");
}
finally
{
   excelWorkbook.Close();
   excelApp.Application.Quit();
   Marshal.ReleaseComObject(excelApp);  
}

For the first time, this error is not there, This error will appear when you are reading the file next time.

edited Sep 3, 2013 at 12:53

answered Sep 3, 2013 at 12:28

Pankaj

2,7803 gold badges27 silver badges50 bronze badges

4 Comments

vin Over a year ago

Does not work, still the same error, the error message box is shown while the point of execution' is in the try block so I don't think adding finally would help.

Pankaj Over a year ago

Kill all the "Excel" processes from Task Managers, and then try it, It should work , Excel is quite stubborn about terminating its processes. I just tried it and it works.

vin Over a year ago

hmmm tried that but no luck, my file does not open at all.. is there something wrong with excelApp.Workbooks.Open(path,0, false, 5, "", "", false, Excel.XlPlatform.xlWindows, "", true, false, 0, true, false, false);

Pankaj Over a year ago

@Vin, this is correct, if it would have been wrong, the file wouldnt have opened in the first iteration, the problem is it didnt got closed properly. Did you tried adding this Marshal.ReleaseComObject(excelApp);

Csaba Toth · Accepted Answer · 2013-09-03 17:10:05Z

0

Try supplying true as a third parameter for Workbooks.Open. MSDN: http://msdn.microsoft.com/en-us/library/office/microsoft.office.interop.excel.workbooks.open.aspx

ReadOnly
    Type: System.Object
    Optional Object. True to open the workbook in read-only mode.

You only want to get values so opening it read-only should be enough for you.

answered Sep 3, 2013 at 17:10

Csaba Toth

10.9k6 gold badges85 silver badges146 bronze badges

Collectives™ on Stack Overflow

unable to open excel file from c# application

3 Answers 3

2 Comments

4 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related