Private points As New ArrayList
    Private draw As Boolean
    Private drawCross As Boolean
    Private cp As Point = New Point(-1, -1)
 
    Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
        Debug.WriteLine("Point: " & (New Point(e.X, e.Y)).ToString())
        Dim np As New Point(e.X, e.Y)
        points.Add(np)
        cp = np
        drawCross = True
        Me.Refresh()
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        draw = True
        drawCross = False
        Me.Refresh()
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        points.Clear()
        draw = False
        drawCross = False
        Me.Refresh()
    End Sub
 
    Private Const csize As Integer = 5
 
    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
        If drawCross Then
            e.Graphics.DrawLine(Pens.Green, cp.X - csize, cp.Y, cp.X + csize, _
              cp.Y)
            e.Graphics.DrawLine(Pens.Green, cp.X, cp.Y - csize, cp.X, cp.Y + _
            csize)
        End If
        If draw Then
            For Each p As Point In points
                Debug.WriteLine("Draw: " & p.ToString())
                e.Graphics.DrawEllipse(Pens.Red, p.X - csize, p.Y - csize, _
                  csize * 2, csize * 2)
            Next
        End If
    End Sub

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