Public Class Form1
' Dim bmp As New System.Drawing.Bitmap("Dateipfad+Name")   ' läd ein Bild in _
  eine Bitmap
    Dim bmp As New Bitmap(300, 300)                 ' legt eine neue Bitmap an
        Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
          System.EventArgs) Handles Button1.Click
        Dim Rnd As New Random
        For i As Int32 = 1 To 1000
            bmp.SetPixel(Rnd.Next(0, 300), Rnd.Next(0, 300), Color.FromArgb( _
              Rnd.Next(0, 256), Rnd.Next(0, 256), Rnd.Next(0, 256)))
        Next
        PictureBox1.Invalidate()
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        PictureBox1.BackColor = Color.Black
        PictureBox1.Image = bmp
    End Sub
End Class