Listview and close form not delete directory - vb.net

Question

My listview codes:
Const IMAGE_DIRECTORY As String = "outfile"
Dim files As String() = Directory.GetFiles(IMAGE_DIRECTORY)
Dim max_length, i As Integer
Dim fname As String
Dim pname As String
Dim myImage As Image
'Set the ColorDepth and ImageSize properties of imageList1.
ImageList1.ColorDepth = ColorDepth.Depth32Bit
ImageList1.ImageSize = New System.Drawing.Size(106, 150)
max_length = files.Length - 1
'Add images to imageList1.
For i = 0 To max_length
pname = Path.GetFullPath(files(i))
myImage = Image.FromFile(pname)
ImageList1.Images.Add(myImage)
myImage = Nothing
Next
pname = Nothing
'ListView1.View = View.LargeIcon
ListView1.LargeImageList = ImageList1
For i = 0 To files.Length - 1
fname = Path.GetFileName(files(i))
Dim listViewItem1 As ListViewItem = New ListViewItem(fname, i)
'Add listViewItem1 and listViewItem2.
ListView1.Items.AddRange(New ListViewItem() {listViewItem1})
listViewItem1 = Nothing
Next
'Me.Controls.AddRange(New Control() {listView1})
ListView1.Items(0).Selected = True
ListView1.Select()
Exit command button and remove files error now:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Me.PictureBox2.Image.Dispose()
Me.ImageList1.Dispose()
Me.PictureBox2.Image.Dispose()
Me.Dispose()
Me.Close()
End Sub
Exit form and remove directory outfile error :
System.IO.IOException was unhandled
   HRESULT = -2147024864
   Message = The process is being used by another process 'Seite0.Jpg' can not access the file.
   Source = mscorlib
What is the code problem ?