How to show window prompt for downloading excel file? - asp.net

Question

I have written code for exporting data to xlsx file. But i dont understand how to show window prompt for downloading that xlsx file at client end.
Here's my code:
Private Sub DataTableToExcel(ByVal tbl As DataTable)
Dim Excel As Object = CreateObject("Excel.Application")
Dim strFilename As String
Dim intCol, intRow As Integer
Dim strPath As String = "C:\"
If Excel Is Nothing Then
MsgBox("It appears that Excel is not installed on this machine. This operation requires MS Excel to be installed on this machine.", MsgBoxStyle.Critical)
Return
End If
Try
With Excel
.SheetsInNewWorkbook = 1
.Workbooks.Add()
.Worksheets(1).Select()
.cells(1, 1).value = "Complaint Detail Report" 'Heading of the excel file
.cells(1, 1).EntireRow.Font.Bold = True
Dim intI As Integer = 1
For intCol = 0 To tbl.Columns.Count - 1
.cells(2, intI).value = tbl.Columns(intCol).ColumnName
.cells(2, intI).EntireRow.Font.Bold = True
intI += 1
Next
intI = 3
Dim intK As Integer = 1
For intCol = 0 To tbl.Columns.Count - 1
intI = 3
For intRow = 0 To tbl.Rows.Count - 1
.Cells(intI, intK).Value = tbl.Rows(intRow).ItemArray(intCol)
intI += 1
Next
intK += 1
Next
If Mid$(strPath, strPath.Length, 1) <> "\" Then
strPath = strPath & "\"
End If
strFilename = strPath & "ComplaintDetail.xlsx"
.ActiveCell.Worksheet.SaveAs(strFilename)
End With
System.Runtime.InteropServices.Marshal.ReleaseComObject(Excel)
Excel = Nothing
MsgBox("Data's are exported to Excel Succesfully: Location: '" & strFilename & "'", MsgBoxStyle.Information)
' Response.AddHeader("content-disposition", "attachment;filename=ComplaintDetail.xlsx")
'Response.ContentType = "application/vnd.excel"
Catch ex As Exception
MsgBox(ex.Message)
End Try
Dim pro() As Process = System.Diagnostics.Process.GetProcessesByName("EXCEL")
For Each i As Process In pro
i.Kill()
Next
End Sub
Here I am saving .XLSX file directly to "C Drive".
Why I choose C Drive? : Because 99% of people have C: in there pc.
But I got some scenario where user don't allow access of their C drive or they don't give permission to write anything inside c drive.
That's why I am trying to add this window prompt where user will decide where to save that file. But i got some issue in above code.
Can you please help me to add window prompt in above code?

Answer 1

Save in the App_Data directory. You can find the absolute path with Server.MapPath("~/App_Data") This path is writeable by the application
Use Response.TransmitFile to make the file to be downloaded.

Answer 2

Try using something like a save file dialog (this can be added via the ui designer).
Then use:
If dialog.Show() = Windows.Forms.DialogResult.OK Then
strPath = dialog.FileName
End If