Error in Opening the Excel file from C#.Net (VS2010)

Question

I am trying to open an excel file (.xlsx) using C# (VS2010 professional) code. I am getting an (untraceable, to me) exception when executing/single stepping the last 2 lines of the below code. Below mentioned is my code for opening an existing excel file.

        string tesfile = "C:\\Users\\AWaheed3\\Desktop\\1.xlsx";
        Microsoft.Office.Interop.Excel.Application xlApp;
        Microsoft.Office.Interop.Excel.Workbook xlWorkBook;
        object misValue = System.Reflection.Missing.Value;
        xlApp = new Microsoft.Office.Interop.Excel.Application();
        xlApp.Visible = true;
        xlWorkBook = xlApp.Workbooks.Open(tesfile, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue);

Also I have included this below line at the start of the code. Further more I have Added the reference of the Microsoft.Office.Interop.Excel from Project->Add Reference (.NET Tab)

 using Microsoft.Office.Interop.Excel;

Can anybody advise why my code is failing/throwing an error?

Regards Asad

EDITED***************************

Here is the message/error I am receiving. Note that the code is failing even while executing the xlApp.Visible = ture line. Error is

Unable to cast COM object of type 'Microsoft.Office.Interop.Excel.ApplicationClass' to interface type 'Microsoft.Office.Interop.Excel._Application'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{000208D5-0000-0000-C000-000000000046}' failed due to the following error: Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)).

Is MS Excel installed on the machine where you run this code? — Andrei, Jun 04 '13 at 08:01
Do you really have to use Excel? Maybe a managed Excel library is a better option. — L-Four, Jun 04 '13 at 08:08
And what is the error you are experiencing? Can you post the message itself? — Andrei, Jun 04 '13 at 08:08

mike27015 · Answer 1 · 2013-06-04T08:24:48.110

0

Try to remove the double backslash and write instead \ or you can do is

Microsoft.Office.Interop.Excel.Application excel = null;
Microsoft.Office.Interop.Excel.Workbook xls = null;
try
{
     excel = new Microsoft.Office.Interop.Excel.Application();
     object missing = Type.Missing;
     object trueObject = true;
     try
     {
          excel.Visible = false; // or true
          excel.DisplayAlerts = false;
     }
     catch(Exception e)
     {
                Console.WriteLine("-------Error hiding the application-------");
                Console.WriteLine("Occured error might be: " + e.StackTrace);
     }
     xls = excel.Workbooks.Open(excelFile, missing, trueObject,    missing,missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing);
     //xls = excel.Workbooks.Open(@"file.xls", missing, trueObject,    missing,missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing);
}
catch (Exception ex)
{
            MessageBox.Show("Error accessing Excel document.\n\n" +
            ex.Message);
}
// Must be surrounded by try catch to work.
// http://naimishpandya.wordpress.com/2010/12/31/hide-power-point-application-window-in-net-office-automation/

The @ removes any issue with the path. Code is similar to yours of course. Just I'm rewriting it in different way. Look for the System.Reflection, I'm using System.Type instead. And some advice for the future, if you work with COM files, try to close them correctly at the end. **Edited.

edited Jun 04 '13 at 08:24

answered Jun 04 '13 at 08:07

mike27015

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The error/code is failing even before coming to open file command. It is failing while executing the Visible command – Asad Waheed Jun 04 '13 at 08:15
Put try/catch between it. I had to do it because you're trying to set the Excel to visible/invisible. – mike27015 Jun 04 '13 at 08:16
You may see the error message in the edited/updated Questions – Asad Waheed Jun 04 '13 at 08:18
Initialize the Interop to null. And put at beginning using library and check if when you write Microsoft.Office. and so on if it does the auto complete – mike27015 Jun 04 '13 at 08:20
It is doing the autocomplete – Asad Waheed Jun 04 '13 at 08:23
Set a try/catch between the visible part and I edited my post accordingly too. – mike27015 Jun 04 '13 at 08:23
Same error, as mentioned above even after putting try/catch for Visible line – Asad Waheed Jun 04 '13 at 08:26
Did you try it from the example I gave you? Because my example is running. – mike27015 Jun 04 '13 at 08:27
Could you try the `excel.Visible=false;` to see if it still fails? – mike27015 Jun 04 '13 at 08:31
Does it still throws you an exception if you try to remove the visible part? And try to get your library and run in command : regsvr32 Microsoft.Office.xx.xx.dll maybe it is corrupted. – mike27015 Jun 04 '13 at 08:33
Yes, it is still showing the same error while commenting out the visible commad.... – Asad Waheed Jun 04 '13 at 08:35
Look if the library is registred correctly, the error you get might be the issue itself not from the code. http://stackoverflow.com/questions/2347529/outlook-2007-from-c-sharp-com-exception-type-e-libnotregistered They talk that maybe the Interop from the Office is corrupted. – mike27015 Jun 04 '13 at 08:38
did you find something to fix it yet? – mike27015 Jun 04 '13 at 09:48

Error in Opening the Excel file from C#.Net (VS2010)

1 Answers1