Public Class Form1
    Dim WithEvents Pb As New PictureBox With {.Dock = DockStyle.Fill, .Parent = _
      Me}
    Dim hgrund As Bitmap = SystemIcons.Shield.ToBitmap
    Dim picList As New List(Of MyPicture)
    Dim loc, pos As Point, img As Int32, mov As Boolean
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.ClientSize = New Size(800, 800)
        For y = 200 To 400 Step 100
            picList.Add(New MyPicture(SystemIcons.Warning.ToBitmap, New _
              Rectangle(225, y, 64, 64)))
            picList.Add(New MyPicture(SystemIcons.Error.ToBitmap, New Rectangle( _
            375, y, 64, 64)))
            picList.Add(New MyPicture(Me.Icon.ToBitmap, New Rectangle(525, y, _
            64, 64)))
        Next
    End Sub
 
    Private Sub Pb_MouseDown(sender As Object, e As MouseEventArgs) Handles _
      Pb.MouseDown
        For i = picList.Count - 1 To 0 Step -1
            If picList(i).Bounds.Contains(e.Location) Then
                loc = e.Location
                pos = New Point(picList(i).Bounds.X, picList(i).Bounds.Y)
                picList.Add(picList(i)) 'aktuelles Bild =
                picList.RemoveAt(i)     'Top-Position
                img = picList.Count - 1
                mov = True
                Exit Sub
            End If
        Next
        mov = False
    End Sub
 
    Private Sub Pb_MouseMove(sender As Object, e As MouseEventArgs) Handles _
      Pb.MouseMove
        If mov AndAlso e.Button = MouseButtons.Left Then
            Dim re As Rectangle = picList(img).Bounds
            picList(img) = New MyPicture(picList(img).Img, New Rectangle(pos.X _
              + e.X - loc.X, pos.Y + e.Y - loc.Y, re.Width, re.Height))
            Pb.Invalidate()
        End If
    End Sub
 
    Private Sub Pb_Paint(sender As Object, e As PaintEventArgs) Handles Pb.Paint
        e.Graphics.InterpolationMode = _
          Drawing2D.InterpolationMode.NearestNeighbor
        e.Graphics.Clear(Color.Green)
        e.Graphics.DrawImage(hgrund, 0, 0, Pb.Width, Pb.Height)
        For Each pic In picList
            e.Graphics.DrawImage(pic.Img, pic.Bounds)
        Next
    End Sub
 
    Private Sub Pb_MouseWheel(sender As Object, e As MouseEventArgs) Handles _
      Pb.MouseWheel
        If Not mov Then Return 'kein Bild ausgewählt
        Dim r As Rectangle = picList(img).Bounds
        If e.Delta > 0 Then
            picList(img) = New MyPicture(picList(img).Img, Rectangle.Inflate(r, _
              4, 4))
        Else
            If r.Width <= 20 OrElse r.Height <= 20 Then Exit Sub ' Mindestgrösse!
            picList(img) = New MyPicture(picList(img).Img, Rectangle.Inflate(r, _
              -4, -4))
        End If
        Pb.Invalidate()
    End Sub
 
    Private Sub PB_MouseEnter(sender As Object, e As EventArgs) Handles _
      Pb.MouseEnter
        Pb.Focus() ' Für Pb.MouseWheel nötig!
    End Sub
 
    Private Sub Form1_Resize(sender As Object, e As EventArgs) Handles Me.Resize
        Pb.Invalidate()
    End Sub
End Class
 
Public Class MyPicture
    Private _img As Bitmap
    Private _bounds As Rectangle
 
    Public Sub New(Img As Bitmap, Rec As Rectangle)
        _img = Img
        _bounds = Rec
    End Sub
 
    Public Property Img As Bitmap
        Get
            Return _img
        End Get
        Set(value As Bitmap)
            _img = Img
        End Set
    End Property
 
    Public Property Bounds As Rectangle
        Get
            Return _bounds
        End Get
        Set(value As Rectangle)
            _bounds = Bounds
        End Set
    End Property
End Class