public void getNumberTest() { int result = ExcelHeader.Excelcolumn_to_number("AZ"); Console.WriteLine(result); result = ExcelHeader.Excelcolumn_to_number("AB"); Console.WriteLine(result); result = ExcelHeader.Excelcolumn_to_number("ZZ"); Console.WriteLine(result); result = ExcelHeader.Excelcolumn_to_number("AAA"); Console.WriteLine(result); }