Convert from .csv file to .xlsx excel file - excel

Question

Hi
I am using an ASP.NET application and producing a report in excel page with .csv extension. However I would like to produce it with .xlsx etension.
The code I am currently using is as follows:
Protected Sub btnSubmit_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSubmit.Click
Dim sql As String
Dim strLine As String = ""
Dim attachment As String = "attachment; filename=PTW.csv"
m_sBranch = ddlBranches.SelectedValue
m_sRegion = ddlAreas.SelectedValue
Dim cnn As SqlConnection = New SqlConnection("Server=XYZ;Database=abc;Trusted_Connection=yes;")
HttpContext.Current.Response.AddHeader("content-disposition", attachment)
HttpContext.Current.Response.ContentType = "text/csv"
cnn.Open()
sql = GetReportSql(m_sBranch, m_sRegion)
Dim cmd As SqlCommand = New SqlCommand(sql, cnn)
Dim dr As SqlDataReader
dr = cmd.ExecuteReader()
HttpContext.Current.Response.Write("PTW JOBS - EXPORTED ON " + DateTime.Now)
For i = 0 To dr.FieldCount - 1
strLine = strLine & dr.GetName(i).ToString & ","
Next
HttpContext.Current.Response.Write(strLine)
Dim sb As StringBuilder = New StringBuilder()
Dim temp As String = ""
While dr.Read()
For i = 0 To dr.FieldCount - 1
temp = temp & dr.GetValue(i)
temp = temp.Replace(",", " ")
sb.Append(temp & ",")
temp = ""
Next
sb.AppendLine()
strLine = ""
End While
HttpContext.Current.Response.Write(sb.ToString())
End Sub
Any help will be highly appreciated. Thanks.

Answer 1

Look into the OpenXML SDK:
I understand that my example doesn't convert .csv files, but it will steer you in the right direction.
http://msdn.microsoft.com/en-us/library/bb448854(office.14).aspx
I've used it in asp.net to create xlsx documents on the fly, streamed directly to the web client:
public static System.IO.MemoryStream ConvertToExcel(DataSet ds)
{
System.IO.MemoryStream stream = new System.IO.MemoryStream();
using (SpreadsheetDocument package = SpreadsheetDocument.Create(stream, SpreadsheetDocumentType.Workbook, true))
{
package.AddWorkbookPart();
package.WorkbookPart.Workbook = new Workbook();
package.WorkbookPart.AddNewPart<WorksheetPart>();
if (ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0)
{
DataTable tbl = ds.Tables[0];
SheetData xlSheetData = new SheetData();
foreach (DataRow row in tbl.Rows)
{
Row xlRow = new Row();
foreach (DataColumn col in tbl.Columns)
{
object cellData = row[col];
Cell xlCell = null;
if (cellData != null)
{
xlCell = new Cell(new InlineString(new DocumentFormat.OpenXml.Spreadsheet.Text(cellData.ToString()))) { DataType = CellValues.InlineString };
}
else
{
xlCell = new Cell(new InlineString(new DocumentFormat.OpenXml.Spreadsheet.Text(String.Empty))) { DataType = CellValues.InlineString };
}
xlRow.Append(xlCell);
}
xlSheetData.Append(xlRow);
}
package.WorkbookPart.WorksheetParts.First().Worksheet = new Worksheet(xlSheetData);
package.WorkbookPart.WorksheetParts.First().Worksheet.Save();
// create the worksheet to workbook relation
package.WorkbookPart.Workbook.AppendChild(new Sheets());
package.WorkbookPart.Workbook.GetFirstChild<Sheets>().AppendChild(new Sheet()
{
Id = package.WorkbookPart.GetIdOfPart(package.WorkbookPart.WorksheetParts.First()),
SheetId = 1,
Name = "Sheet1"
});
package.WorkbookPart.Workbook.Save();
}
}
return stream;
}

Answer 2

Shariful, from what I've read (not tried yet), I believe the best method is to set your HTTP Response headers as outlined here.
In short, the key seems to be setting the content-disposition header to "attachment".
e.g.:
Content-Disposition: attachment; filename=<file name.ext>
Sorry that I haven't tested this, but in my searching for something closely related, almost every place I went suggests to use this method in order to force download dialog.