title: How to create a new worksheet in Excel file c#?
body: <p>I need to create a very big Excel file, but excel file in one worksheet can contain up to 65k rows. So, i want to divide all my info into several worksheets dynamical.
  This is my approximate code</p>
  
  <pre><code> //------------------Create Excel App--------------------
  Excel.Application xlApp;
  Excel.Workbook xlWorkBook;
  Excel.Worksheet xlWorkSheet;
  object misValue = System.Reflection.Missing.Value;
  
  xlApp = new Excel.Application();
  xlWorkBook = xlApp.Workbooks.Add(misValue);
  xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(numberOfLetters);
  
       foreach (string letter in letters)
       {
        xlWorkSheet.Cells[rowIndex, 1] = letter; 
        rowIndex++;
       }
  
  xlWorkBook.SaveAs(pathXL, Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
  xlWorkBook.Close(true, misValue, misValue);
  xlApp.Quit();
  </code></pre>
  
  <p>How I can add new worksheet inside of my foreach loop and using some condition give a name to worksheet (which user can see in Excel at the bottom of the page in list)?</p>
  
  <p>Some like that</p>
  
  <pre><code>    foreach (string letter in letters)
      {
        if (letter == SOME)
        {
          AddNewWorksheet and give name SOME
        }
          xlWorkSheet.Cells[rowIndex, 1] = letter; 
          rowIndex++;
      }
  </code></pre>
  
  <p>And how to save all worksheets at the end?</p>