Excel Interop - Add a new worksheet after all of the others

Question

I am trying to add a new worksheet to an Excel workbook and make this the last worksheet in the book in C# Excel Interop.

It seems really simple, and I thought the below code would do it:

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

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            var excel = new Excel.Application();

            var workbook = excel.Workbooks.Open(@"C:\test\Test.xlsx");
            workbook.Sheets.Add(After: workbook.Sheets.Count);

            workbook.Save();
            workbook.Close();

            Marshal.ReleaseComObject(excel);
        }
    }
}

No such luck. I get this helpful error:

COMException was unhandled - Exception from HRESULT: 0x800A03EC

I found this page on Microsoft.com which suggested I try and add the sheet first and then move it so I tried that as shown below. I know that this webpage targets Excel 95 but the VBA is still there to use so I was hoping it would still work:

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

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            var excel = new Excel.Application();

            var workbook = excel.Workbooks.Open(@"C:\test\Test.xlsx");
            workbook.Sheets.Add();
            workbook.Sheets.Move(After: workbook.Sheets.Count);

            workbook.Save();
            workbook.Close();

            Marshal.ReleaseComObject(excel);
        }
    }
}

I get the same error as above. I have also tried passing the name of my last worksheet as a string as the After parameter in both the Add and Move methods, no joy!

That is what I have tried, so my question is how do I add a worksheet to an Excel workbook and make this the last sheet in the workbook using C# Excel Interop?

Thanks

JMK - not an answer to your issue but perhaps a helpful pointer for c# and excel. I've been using the LinqToExcel library for quite some time and really can't express how much cleaner an experience it is VS using interop methodology. If you have the time, take a look at it to see if it'll fit with your requirements. github.com/paulyoder/LinqToExcel also code.google.com/p/linqtoexcel — jim tollan
@jimtollan Thankyou for the heads up, I will make a point of checking out LinqToExcel, it looks good. Thanks! — JMK

Dave Dave · Accepted Answer · 2012-08-28T09:28:26

Looking at the documentation here http://msdn.microsoft.com/en-us/library/microsoft.office.tools.excel.worksheet.move(v=vs.80).aspx, it indicates that the 'after' object isn't a numerical position; it's the object representing the sheet you want to position your sheet after. The code should probably be something like (untested):

workbook.Sheets.Add(After: workbook.Sheets[workbook.Sheets.Count]);

Excel Interop - Add a new worksheet after all of the others

4 Answers