title: Transparent panel does not render scrollbar correctly
body: <p>I wanted my panel to be truly transparent, so I followed the instructions on this article:
  <a href="https://web.archive.org/web/20121226091810/http://www.bobpowell.net/transcontrols.htm" rel="nofollow noreferrer">https://web.archive.org/web/20121226091810/http://www.bobpowell.net/transcontrols.htm</a></p>
  <p>However, I've forced my panel to always show the Vertical scroll bar. It initially is not rendered unless I hover my mouse cursor over it, at which point it begins to appear. What more can be added to the above article to ensure that my panel's scrollbars are always visible, other than setting VerticalScroll.Visible to true?</p>
  <p>Here is what I have so far for my custom Panel class. This is using C# .NET 4.0 in Visual Studio 2010:</p>
  <pre><code>public class SkinnedList : Panel
  {
      protected override CreateParams CreateParams
      {
          get
          {
              CreateParams cp = base.CreateParams;
              cp.ExStyle |= 0x00000020; // WS_EX_TRANSPARENT
              return cp;
          }
      }
  
      public SkinnedList()
      {
          AdjustFormScrollbars( true );
      }
  
      public new void AdjustFormScrollbars( bool visible )
      {
          VerticalScroll.Visible = true;
          HorizontalScroll.Visible = false;
      }
  
      protected override void OnPaint(PaintEventArgs e)
      {
          base.OnPaint(e);
      }
  
      protected override void OnPaintBackground(PaintEventArgs e)
      {
          // Do not render background
      }
  
      protected void InvalidateEx()
      {
          if( Parent != null )
          {
              Rectangle rc = new Rectangle( Location, Size );
              Parent.Invalidate( rc, true );
          }
      }
  }
  </code></pre>