Public Class Form1
    Dim LogInhalt As New List(Of String)
    Dim LogDatei As String = "C:\LogTest\Protokoll.log"
 
    ' Verwendete Steuerelemente
    ' 1x ListBox
    ' 1x CheckBox 
    ' 1x Textbox
    ' 1x Button
 
    Private Sub FormMain_Load(ByVal sender As System.Object, _
                              ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            Me.LoadLog(LogDatei, LogInhalt, ListBox1)
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, _
                              ByVal e As System.EventArgs) Handles Button1.Click
        Me.AddLog(TextBox1.Text, ListBox1, LogInhalt, CheckBox1.Checked)
        Me.SaveLog(LogInhalt, LogDatei)
    End Sub
 
 
    Private Sub AddLog(ByVal Eintrag As String, _
                       ByRef Anzeige As ListBox, _
                       ByRef LogInhaltListe As List(Of String), _
                       Optional ByVal AnErsterStelle As Boolean = True)
        Try
            Anzeige.DataSource = Nothing
            If AnErsterStelle Then
                LogInhaltListe.Insert(0, Eintrag)
            Else
                LogInhaltListe.Add(Eintrag)
            End If
            Anzeige.DataSource = LogInhaltListe
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation, "AddLog")
        End Try
    End Sub
 
    Private Sub LoadLog(ByVal Datei As String, _
                        ByRef LogInhaltListe As List(Of String), _
                        ByVal Anzeige As ListBox)
        Try
            If Not IO.File.Exists(Datei) Then Return
 
            LogInhaltListe.Clear()
            LogInhaltListe.AddRange(IO.File.ReadAllLines(Datei, _
                                                         System.Text.Encoding.D_
                                                         efault))
            Anzeige.DataSource = LogInhaltListe
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation, "LoadLog")
        End Try
    End Sub
 
    Private Sub SaveLog(ByRef LogInhaltListe As List(Of String), _
                        ByVal Datei As String)
        Try
            Dim fInfo As New IO.FileInfo(Datei)
            If Not fInfo.Directory.Exists Then fInfo.Directory.Create()
            IO.File.WriteAllLines(fInfo.FullName, _
                                  LogInhaltListe.ToArray, _
                                  System.Text.Encoding.Default)
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation, "SaveLog")
        End Try
    End Sub
End Class