title: PictureBox2.Image = PictureBox1.Image seems to be linking the boxes instead of copying the image over?
body: <h2>The Problem</h2>
  
  <p>I have a simple form with 2 PictureBoxes</p>
  
  <p>I allow the user to draw on <em>PictureBox1</em>
  When I click a <em>Butto</em>n on the form I want to capture the image in <em>PictureBox1</em> and store it in <em>PictureBox2</em></p>
  
  <p>The issue is that if I add the line:
      <strong>PictureBox2.Image = PictureBox1.Image</strong>
  Any updates to <em>PictureBox1</em> are immediately reflected in <em>PictureBox2</em> ?!?</p>
  
  <p>I just want to capture the image in <em>PictureBox1</em> at that moment in time so that I can use it to 'Undo'</p>
  
  <h2>Tech</h2>
  
  <p>It's a Windows Forms App in Visual Basic, .Net 4.7.2 using Visual Studio 2019 Preview</p>
  
  <h2>Code</h2>
  
  <pre><code>Public Class Form1
  
      Dim drawMouseDown = False ' Set initial mouse state to not clicked
      Dim drawMyBrush As New Pen(Brushes.White, 20) 'Set up the Brush
      Public drawCanvas As New Bitmap(245, 352) 'Set up Bitmap Canvas
  
      Private Sub btn_Color_Yellow_Click(sender As Object, e As EventArgs) Handles btn_Color_Yellow.Click
          drawMyBrush.Brush = Brushes.Yellow
          drawMyBrush.Width = 20
      End Sub
  
      Private Sub PictureBox1_MouseDown(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseDown
          drawMouseDown = True
      End Sub
  
      Private Sub PictureBox1_MouseUp(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseUp
          drawMouseDown = False
      End Sub
  
      Private Sub PictureBox1_MouseMove(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseMove
          Dim g As Graphics = Graphics.FromImage(drawCanvas)
          Static coord As New Point
          If drawMouseDown Then
              g.SmoothingMode = Drawing2D.SmoothingMode.HighQuality
              drawMyBrush.StartCap = Drawing2D.LineCap.Round
              drawMyBrush.EndCap = Drawing2D.LineCap.Round
              g.DrawLine(drawMyBrush, coord.X, coord.Y, e.X, e.Y)
              g.Dispose()
              PictureBox1.Image = drawCanvas
              Me.Refresh()
          End If
          coord = e.Location
      End Sub
  
      Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
          PictureBox2.Image = PictureBox1.Image 'Why does this not just update the PicBox2 image once?!? (or only when the Button is clicked)
      End Sub
  
  End Class
  </code></pre>
  
  <h2>Expectation</h2>
  
  <p>When <em>Button1</em> is clicked I expect <em>PictureBox2</em> to contain the <em>PictureBox1</em> image, when I continue to draw on <em>PictureBox1</em> I do <strong>NOT</strong> expect it to keep updating <em>PictureBox2</em> as the user is drawing on the other!</p>