.NET : Smooth Scrolling Panel

Windows raises ThumbTrack ScrollEvent while dragging Scrollbar. And if your System Visual Effects are optimized for performance, window contents are updated only when scollbar stops ( unlike browser)- that looks ugly and annoying.

To solve this I just substituted all SB_THUMBTRACK messeges with SB_THUMBPOSITION. Not very pretty, but works. The following code is in C#.

public class ScrollPanel : System.Windows.Forms.Panel
{
   private const int WM_HSCROLL = 0x114;
   private const int WM_VSCROLL = 0x115;

   protected override void WndProc (ref Message m)
   {
      if ((m.Msg == WM_HSCROLL || m.Msg == WM_VSCROLL) 
          && (((int)m.WParam & 0xFFFF) == 5))
      {
          // Change SB_THUMBTRACK to SB_THUMBPOSITION
         m.WParam = (IntPtr)(((int)m.WParam & ~0xFFFF) 
                    | 4);
      }
      base.WndProc (ref m);
   }
}