title: Transparent background for MFC-hosted Windows Forms UserControl
body: <p>I am using CWinFormsControl to host a Windows Forms UserControl in an MFC dialog. I have set the property <code>DoubleBufferd</code> to true. According to the docs this results in <code>AllPaintingInWmPaint</code> and <code>UserPaint</code> to be set to true too (not sure if this matters). How can I force (or fake) the UserControl to draw its background transparent?</p>
  
  <p>This is what I have set in the contructor of my UserControl:</p>
  
  <pre><code>this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
  this.BackColor = Color.Transparent;
  this.DoubleBuffered = true;
  </code></pre>