VB : systeme en cours d utilisation par un autre processus

Bonjour, je sais que ce sujet semble clos.. mais je me suis fié sur les réponses données ici. Malheureusement j'ai un léger soucis, le code ne semble pas fonctionner à un ou deux près. J'ai mis en gras et souligné mon problème. Avant de lancer l'application, tout va bien. Mais lorsque j'ai choisi l'emplacement et clique sur enregistrer, une erreur me parvient : systeme en cours d utilisation par un autre processus Le fichier est bel et bien créé, mais ne comporte rien (0 ko). Merci pour votre aide

Imports System.IO

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles Button1.Click
        ' Displays a SaveFileDialog so the user can save the Image
        ' assigned to Button2.
        Dim saveFileDialog1 As New SaveFileDialog()
        saveFileDialog1.Filter = "Routier file|*.rout"
        saveFileDialog1.Title = "Save an Routier File"
        saveFileDialog1.ShowDialog()

        ' If the file name is not an empty string open it for saving.
        If saveFileDialog1.FileName <> "" Then
            ' Saves the Image via a FileStream created by the OpenFile method.
            Dim fs As System.IO.FileStream = CType _
               (saveFileDialog1.OpenFile(), System.IO.FileStream)
            Using outfile As New StreamWriter(saveFileDialog1.FileName)
                outfile.Write(TextBox1.Text)
                outfile.Write(CheckBox2.Text)
                outfile.Write(CheckBox1.Text)
            End Using
            Select Case saveFileDialog1.FilterIndex
            End Select

            fs.Close()
        End If
    End Sub



    Private Sub Button2_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim myStream As Stream = Nothing
        Dim openFileDialog1 As New OpenFileDialog()

        openFileDialog1.InitialDirectory = "c:\"
        openFileDialog1.Filter = "Routier file (*.rout)|*.rout|All files (*.*)|*.*"
        openFileDialog1.FilterIndex = 2
        openFileDialog1.RestoreDirectory = True

        If openFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OK Then

        End If
        Try

        Catch ex As Exception

        End Try
        myStream = openFileDialog1.OpenFile()
        If (myStream IsNot Nothing) Then

        End If
        ' Insert code to read the stream here.
        Using sr As New StreamReader(openFileDialog1.FileName)
            TextBox1.Text = sr.ReadLine()
            CheckBox2.Text = sr.ReadLine()
            CheckBox1.Text = sr.ReadLine()
        End Using
        Try
        Catch Ex As Exception
            MessageBox.Show("Cannot read file from disk. Original error: " & Ex.Message)
        Finally
            ' Check this again, since we need to make sure we didn't throw an exception on open.
            If (myStream IsNot Nothing) Then
                myStream.Close()
            End If
        End Try
    End Sub
End Class