public class ImportExportController : ControllerBase
 {
  private readonly IHostingEnvironment _hostingEnvironment;

  public ImportExportController(IHostingEnvironment hostingEnvironment)
  {
   _hostingEnvironment = hostingEnvironment;
  }
 }

  [HttpGet]
  public string Export()
  {
   string sWebRootFolder = _hostingEnvironment.WebRootPath;
   string sFileName = @"demo.xlsx";
   string URL = string.Format("{0}://{1}/{2}", Request.Scheme, Request.Host, sFileName);
   FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
   if (file.Exists)
   {
    file.Delete();
    file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
   }
   using (ExcelPackage package = new ExcelPackage(file))
   {
    // add a new worksheet to the empty workbook
    ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("Employee");
    //First add the headers
    worksheet.Cells[1, 1].Value = "ID";
    worksheet.Cells[1, 2].Value = "Name";
    worksheet.Cells[1, 3].Value = "Gender";
    worksheet.Cells[1, 4].Value = "Salary (in $)";

    //Add values
    worksheet.Cells["A2"].Value = 1000;
    worksheet.Cells["B2"].Value = "Jon";
    worksheet.Cells["C2"].Value = "M";
    worksheet.Cells["D2"].Value = 5000;

    worksheet.Cells["A3"].Value = 1001;
    worksheet.Cells["B3"].Value = "Graham";
    worksheet.Cells["C3"].Value = "M";
    worksheet.Cells["D3"].Value = 10000;

    worksheet.Cells["A4"].Value = 1002;
    worksheet.Cells["B4"].Value = "Jenny";
    worksheet.Cells["C4"].Value = "F";
    worksheet.Cells["D4"].Value = 5000;

    package.Save(); //Save the workbook.
   }
   return URL;
  }

using (var cells = worksheet.Cells[1, 1, 1, 4])
    {
     cells.Style.Font.Bold = true;
     cells.Style.Fill.PatternType = ExcelFillStyle.Solid;
     cells.Style.Fill.BackgroundColor.SetColor(Color.LightGray);
    }

[HttpGet]
  [Route("Import")]
  public string Import()
  {
   string sWebRootFolder = _hostingEnvironment.WebRootPath;
   string sFileName = @"demo.xlsx";
   FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
   try
   {
    using (ExcelPackage package = new ExcelPackage(file))
    {
     StringBuilder sb = new StringBuilder();
     ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
     int rowCount = worksheet.Dimension.Rows;
     int ColCount = worksheet.Dimension.Columns;
     bool bHeaderRow = true;
     for (int row = 1; row <= rowCount; row++)
     {
      for (int col = 1; col <= ColCount; col++)
      {
       if (bHeaderRow)
       {
        sb.Append(worksheet.Cells[row, col].Value.ToString() + "\t");
       }
       else
       {
        sb.Append(worksheet.Cells[row, col].Value.ToString() + "\t");
       }
      }
      sb.Append(Environment.NewLine);
     }
     return sb.ToString();
    }
   }
   catch (Exception ex)
   {
    return "Some error occured while importing." + ex.Message;
   }
  }