Imports System.Data
Imports System.Data.Common
Imports System.Data.SqlClient
Imports System.IO
Imports System.Text
Imports System.Data.OleDb
Imports Excel = Microsoft.Office.Interop.Excel

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click

 Dim i As Integer
        Dim strLine As String, filePath, fileName, fileExcel
        Dim objFileStream As FileStream
        Dim objStreamWriter As StreamWriter
        Dim nRandom As Random = New Random(DateTime.Now.Millisecond)

        Dim cnn As SqlConnection = New SqlConnection(con_string)

        'Create a pseudo-random file name.
        fileExcel = "Foglio " & nRandom.Next().ToString() & ".xls"

        'Set a virtual folder to save the file.
        'Make sure that you change the application name to match your folder.
        filePath = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
        fileName = filePath & "\" & fileExcel

        'Use FileStream to create the .xls file.
        objFileStream = New FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Write)
        objStreamWriter = New StreamWriter(objFileStream)

        'Use a DataReader to connect to the Pubs database.
        cnn.Open()
        Dim sql As String = "select * from info"
        Dim cmd As SqlCommand = New SqlCommand(sql, cnn)

        Dim dr As SqlDataReader
        dr = cmd.ExecuteReader()

        'Enumerate the field names and records that are used to build the file.
        For i = 0 To dr.FieldCount - 1
            strLine = strLine & dr.GetName(i).ToString & Chr(9)
        Next

        'Write the field name information to file.
        objStreamWriter.WriteLine(strLine)

        'Reinitialize the string for data.
        strLine = ""

        'Enumerate the database that is used to populate the file.
        While dr.Read()
            For i = 0 To dr.FieldCount - 1
                strLine = strLine & dr.GetValue(i) & Chr(9)
            Next
            objStreamWriter.WriteLine(strLine)
            strLine = ""
        End While

        'Clean up.
        dr.Close()
        cnn.Close()
        objStreamWriter.Close()
        objFileStream.Close()

        System.Diagnostics.Process.Start(filename,filePath)