Private lines() As String
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        Dim sr As New IO.StreamReader("F:\Work Dev\VSNet" & _
        "Dev\Test\readlinesfromkeypointintolistbox.txt", _
        System.Text.Encoding.Default)
        lines = Split(sr.ReadToEnd, vbCrLf)
        sr.Close()
        For i As Integer = 0 To UBound(lines)
            If Microsoft.VisualBasic.Left(lines(i), 2) = "##" Then
                ComboBox1.Items.Add(lines(i))
            End If
        Next
        ComboBox1.SelectedIndex = 0
    End Sub
 
    Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
        Dim i As Integer = Array.IndexOf(lines, ComboBox1.SelectedItem)
        If i > -1 Then
            ListBox1.Items.Clear()
            For i = i + 1 To UBound(lines)
                If Microsoft.VisualBasic.Left(lines(i), 2) = "##" Then Exit Sub
                ListBox1.Items.Add(lines(i))
            Next
        End If
    End Sub