How do I save an Excel file without getting a format warning when opening, using C# and Excel 2010
问题 I'm using Excel 2010. I'm trying so save my excel file, with this code. It does save a .xls file, but when I open the file I get this message: The file you are trying to open, 'tre.xls', is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a thrusted source before opening the file. Do you want to open the file now? If I press yes the file opens. But what do I need to get rid of this format-popup? My code: using System; using System