Public Class frmInvokeTest
 
    Dim picturebox1 As New PictureBox With _
          {.Parent = Me, .Width = 190, .Height = 300}
    Dim WithEvents btnStart As New Button With _
          {.Parent = Me, .Left = 200}
 
    Dim Timer1 As System.Threading.Timer
 
    Private Delegate Sub Delegate_SetPictureBox1_Thread(ByVal ImageIN As  _
      Image)
 
 
    Sub Start_Timer()
 
        Dim autoEvent As New System.Threading.AutoResetEvent(False)
        Dim TmpCallback As System.Threading.TimerCallback = AddressOf _
          Me.HLP_Timer_Tick
 
        Timer1 = New System.Threading.Timer(TmpCallback, autoEvent, 0, 1000)
 
    End Sub
 
 
    Private Sub HLP_Timer_Tick(ByVal stateInfo As Object)
 
        'Hier später Code rein um Bild auszuwählen
        Me.HLP_SetPicture_MASCHINENBILD(Nothing)
    End Sub
 
 
    Sub Stop_Timer()
 
        Dim strTimer As String = Nothing
 
        'Herausfinden ob Timer überhaupt initialisiert wurde
        Try
            strTimer = Me.Timer1.ToString
        Catch
            GoTo fastExit
        End Try
 
        Me.Timer1.Dispose()
 
fastExit:
    End Sub
 
 
    Sub HLP_SetPicture_MASCHINENBILD(ByVal ImageIN As Image)
 
        Try
            Me.Invoke(New Delegate_SetPictureBox1_Thread(AddressOf _
              SetPictureBox1_Thread), New Object() {ImageIN})
        Catch
            Dim _Breakpoint As Integer = 0
        End Try
 
    End Sub
 
 
    Sub SetPictureBox1_Thread(ByVal ImageIN As Image)
        Dim Random1 As System.Random = Nothing
        Dim bBuffer(3 - 1) As Byte
 
        Random1 = New System.Random()
        Random1.NextBytes(bBuffer)
 
        Dim vl As Integer
        Integer.TryParse(Me.Text, vl)
        Me.Text = CStr(vl + 1)
 
        Me.picturebox1.BackColor = System.Drawing.Color.FromArgb(bBuffer(0), _
          bBuffer(1), bBuffer(2))
 
        Me.PictureBox1.Show()
        Me.PictureBox1.Refresh()
    End Sub
 
    Private Sub btnStart_Click(sender As Object, _
        e As System.EventArgs) Handles btnStart.Click
 
        Start_Timer()
 
    End Sub
End Class