Public Class Form1
    Inherits System.Windows.Forms.Form
#Region " Vom Windows Form Designer generierter Code "
' ...
#End Region
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim arr As New ArrayList
        For Each f As String In IO.Directory.GetFiles("C:\Windows")
            arr.Add(New MyFilesCollection(f, New IO.FileInfo(f).Length))
        Next
        arr.Sort(New MyFilesCollection.MyComparer) '// Sortieren nach der Grösse
        Me.ListBox1.Items.AddRange(arr.ToArray(GetType(MyFilesCollection)))
    End Sub
    Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
        Dim f As MyFilesCollection = CType(Me.ListBox1.SelectedItem, _
        MyFilesCollection)
        MessageBox.Show(f.ToString)
    End Sub
End Class
 
Public Class MyFilesCollection
    Public Class MyComparer
        Implements IComparer
        Public Function Compare(ByVal x As Object, ByVal y As Object) As _
          Integer Implements System.Collections.IComparer.Compare
            Dim f1 As MyFilesCollection = CType(x, MyFilesCollection)
            Dim f2 As MyFilesCollection = CType(y, MyFilesCollection)
            If f1.FileSize < f2.FileSize Then Return -1
            If f1.FileSize = f2.FileSize Then Return 0
            If f1.FileSize > f2.FileSize Then Return 1
        End Function
    End Class
    Private _FileName As String
    Private _FileSize As Long
    Public Sub New(ByVal FileName As String, ByVal FileSize As Double)
        Me._FileName = FileName
        Me._FileSize = FileSize
    End Sub
    Public Overrides Function ToString() As String
        Return String.Format("Filename: {0}  -  Filesize: {1} KByte", _
          Me._FileName, (Me._FileSize \ 1024).ToString("N0"))
    End Function
    Public Property FileName() As String
        Get
            Return Me._FileName
        End Get
        Set(ByVal Value As String)
            Me._FileName = Value
        End Set
    End Property
    Public Property FileSize() As Double
        Get
            Return Me._FileSize
        End Get
        Set(ByVal Value As Double)
            Me._FileSize = Value
        End Set
    End Property
End Class