Export to csv in debug mode success but in run-time mode it fails - sql

Question

I am reading records from a SQL Server table into a dataset and then exporting it to a CSV file. When I step through it in debug mode, everything works fine. When I run it, it exports just one cell with crap data. Since it is an ASP.NET application I am not sure if I am doing something wrong regarding postbacks. It seems in run-time, it doesn't wait for the CSV file to be written.
Dim sbldRecordCSV As New StringBuilder
Dim dtHCMTable As DataTable = mdsHCMTable.Tables(0)
Dim intIndex As Integer = 0
'Read the connection-string from web.config
Dim connHCM As New SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings("connHCM").ConnectionString)
'Read the exported CSV file path from web.config
Dim strCSVpath As String = System.Configuration.ConfigurationManager.AppSettings("CSVpath").ToString
Try
For intIndex = 0 To mdsHCMTable.Tables(0).Rows.Count - 1
Dim drHCMTable As DataRow = dtHCMTable.Rows(intIndex)
For Each field As Object In drHCMTable.ItemArray
sbldRecordCSV.Append(field.ToString & "|")
Next
sbldRecordCSV.Replace("|", vbNewLine, sbldRecordCSV.Length - 1, 1)
Next
My.Computer.FileSystem.WriteAllText(strCSVpath.ToString & lstDataTables.SelectedValue.ToString & ".csv", sbldRecordCSV.ToString, False)

Answer 1

After some searching around I realized that I neede to modify the ExportCSV code. The modified routine is as follows:
Protected Sub ExportToCSV(mdsHCMTable As DataSet)
Dim dt As DataTable = mdsHCMTable.Tables(0)
'Read the exported CSV file path from web.config
Dim strCSVpath As String = System.Configuration.ConfigurationManager.AppSettings("CSVpath").ToString
Response.Clear()
Response.Buffer = True
Response.AddHeader("content-disposition", "attachment;filename=" & lstDataTables.SelectedValue.ToString & ".csv")
Response.Charset = ""
Response.ContentType = "application/text"
Dim sb As New StringBuilder()
For k As Integer = 0 To dt.Columns.Count - 1
'add separator
sb.Append(dt.Columns(k).ColumnName + "|"c)
Next
'append new line
sb.Append(vbCr & vbLf)
For i As Integer = 0 To dt.Rows.Count - 1
For k As Integer = 0 To dt.Columns.Count - 1
'add separator
sb.Append(dt.Rows(i)(k).ToString().Replace(",", "|") + "|"c)
Next
'append new line
sb.Append(vbCr & vbLf)
Next
Response.Clear()
Response.BufferOutput = False
Response.Output.Write(sb.ToString())
Response.Flush()
End Sub
This solution worked for me. I hope it can be helpful to others.