Not able to read excel sheet saved as xls using closedxml - excel

Question

I have the below code to save the data in excel sheet as .xls
public ActionResult ExportToExcel()
{
DataTable tbl = CopyGenericToDataTable(res);
tbl.TableName = "InvalidInvoices";
using (XLWorkbook wb = new XLWorkbook())
{
wb.Worksheets.Add(tbl);
wb.Style.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
wb.Style.Font.Bold = true;
Response.Clear();
Response.Buffer = true;
Response.Charset = "";
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", "attachment;filename= "+fileName + ".xls");
using (MemoryStream MyMemoryStream = new MemoryStream())
{
wb.SaveAs(MyMemoryStream);
MyMemoryStream.WriteTo(Response.OutputStream);
Response.Flush();
Response.End();
}
}
}
Above is code which download the xls excel sheet at client side. It works fine the data gets saved in excel sheet.
Problem is if I try to upload this same file using below code -
if (files != null)
{
HttpPostedFileBase upload = files.FirstOrDefault();
Stream stream = upload.InputStream;
DataSet result = new DataSet();
if (upload != null && upload.ContentLength > 0)
{
if (upload.FileName.EndsWith(".xls") || upload.FileName.EndsWith(".xlsx"))
{
// ExcelDataReader works with the binary Excel file, so it needs a FileStream
// to get started. This is how we avoid dependencies on ACE or Interop:
// We return the interface, so that
IExcelDataReader reader = null;
if (upload.FileName.EndsWith(".xls"))
{
reader = ExcelReaderFactory.CreateBinaryReader(stream);
}
else if (upload.FileName.EndsWith(".xlsx"))
{
reader = ExcelReaderFactory.CreateOpenXmlReader(stream);
}
reader.IsFirstRowAsColumnNames = false;
result = reader.AsDataSet();
reader.Close();
}
}
}
In above code I am getting error in ExcelReaderFactory.CreateBinaryReader(stream);
In stream it has the values in bytes too just on using createBinaryreader of excelreaderfactory reader has error message as 'Invalid file signature'.
Any help will be highly appreciated.

Answer 1

ClosedXML generates .xlsx files, not .xls files.
Check your code:
Response.AddHeader("content-disposition", "attachment;filename= "+fileName + ".xls");