How to Delete a Column Programmatically?

Here you find how to do it:

http://bytes.com/topic/c-sharp/answers/258110-how-do-you-delete-excel-column

http://quicktestprofessional.wordpress.com/2008/02/14/delete-columns-from-xl-sheet/

Here is the solution to make it clearer (thanks to Leniel for the link)

Excel.Range range = (Excel.Range)sheet.get_Range("C1", Missing.Value);
range.EntireColumn.Delete(Missing.Value);
System.Runtime.InteropServices.Marshal.ReleaseComObject(range);

This was the first result I hit and deleting a column in Excel doesn't need as much code as the current answers suggest. In fact (assuming you have a Worksheet object already, listed below as mySheet) all that is needed for the original question is:

mySheet.Columns["C"].Delete();

If you want to delete multiple columns then:

mySheet.Columns["C:D"].Delete();

You can specify a variable in the Delete method (see https://docs.microsoft.com/en-us/dotnet/api/microsoft.office.interop.excel.xldeleteshiftdirection?view=excel-pia) i.e. mySheet.Columns["C"].Delete(xlShiftToLeft)but there's no need as the Delete method is smart enough to realise that the Range you are selecting is a single column, so will do this automatically.

You can also uses a numeric value to designate the column i.e. mySheet.Columns[2].Delete()