How to Change Imagelist image size while Listview is active and contains items?

OK here is the code:

[code]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
For Each fileName As String In IO.Directory.GetFiles("C:\")
ImageList1.Images.Add(Icon.ExtractAssociatedIcon(fileName))
ListView1.Items.Add(IO.Path.GetFileName(fileName), ImageList1.Images.Count - 1)
Next
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim OpenFile As New OpenFileDialog
With OpenFile
.Multiselect = True
If .ShowDialog = Windows.Forms.DialogResult.OK Then
For Each fileName As String In .FileNames
ImageList1.Images.Add(Icon.ExtractAssociatedIcon(fileName))
ListView1.Items.Add(IO.Path.GetFileName(fileName), ImageList1.Images.Count - 1)
Next
End If
End With
End Sub

Private Sub TrackBar1_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TrackBar1.Scroll
If Me.TrackBar1.Value = 0 Then
ImageList1.ImageSize = New Size(16, 16)
ElseIf Me.TrackBar1.Value = 1 Then
ImageList1.ImageSize = New Size(20, 20)
ElseIf Me.TrackBar1.Value = 2 Then
ImageList1.ImageSize = New Size(24, 24)
ElseIf Me.TrackBar1.Value = 3 Then
ImageList1.ImageSize = New Size(32, 32)
End If
End Sub

[/code]