C# How to work with Excel. Simple example.

using Excel = Microsoft.Office.Interop.Excel; 
        
void CreateExcel()
        {
            Excel.Application xlApp;
            Excel.Workbook xlWorkBook;
            Excel.Worksheet xlWorkSheet;
            object misValue = System.Reflection.Missing.Value;

            xlApp = new Excel.Application();//new Excel.ApplicationClass();
            xlWorkBook = xlApp.Workbooks.Add(misValue);

            xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);


            int i = 3;
            int j = 0;
            xlWorkSheet.Cells[1, 1] = "Protocol from " + DateTime.Now.ToShortDateString();
            Excel.Range rg = (Excel.Range)xlWorkSheet.Cells[1, 1];
            rg.EntireColumn.NumberFormat = "MM/DD/YYYY";

            xlWorkSheet.Columns.AutoFit();
                
            xlWorkBook.SaveAs("sdfgsdfg.xls", Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, Excel.XlSaveConflictResolution.xlLocalSessionChanges, misValue, misValue, misValue, misValue);
            xlWorkBook.Close(true, misValue, misValue);
            xlApp.Quit();

            releaseObject(xlWorkSheet);
            releaseObject(xlWorkBook);
            releaseObject(xlApp);
        }

        private void releaseObject(object obj)
        {
            try
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
                obj = null;
            }
            catch (Exception ex)
            {
                obj = null;
            }
            finally
            {
                GC.Collect();
            }
        }