Question

I am unable to export my data into excel.
I have tried the suggestions on S/O, but have not had any luck.

        Dim sqlString As String = "spExportRateProfile" & Session("OfficeNumber") & "," & Session("SalesRepID")
        Dim conn As SqlConnection = New SqlConnection(Utils.GetConfigKey("ConnectionStringVimas"))
        conn.Open()
        Dim dt As DataTable = New DataTable()
        Dim da As SqlDataAdapter = New SqlDataAdapter(sqlString, conn)
        da.Fill(dt)

        Response.AddHeader("content-disposition", "attachment;filename=ReportExport.xlsx")
        Response.ContentType = "application/vnd.ms-excel"  

What do I need do after this to export my data to excel?

Answer 1

You could use a ExcelLibrary like EPPlus(GPL) which i can warmly recommend.

Then it is as easy as this to create Excel-Files from a DataTable and write it to the Response:

Dim pck = New ExcelPackage()
Dim ws = pck.Workbook.Worksheets.Add("Worksheet-Name")
ws.Cells("A1").LoadFromDataTable(dt, True, OfficeOpenXml.Table.TableStyles.Medium1)
Response.Clear()
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
Response.AddHeader("content-disposition", "attachment;  filename=ExcelFileName.xlsx")
Response.BinaryWrite(pck.GetAsByteArray())

Here is another example: http://epplus.codeplex.com/wikipage?title=WebapplicationExample