Grabs the content of a Windows Control and returns its bitmap image -- especially useful for long running operations where you might want to "dim" the control a put a spinner on top of it.

GrabControlBitmapImage.cs

/*
  GrabControlBitmapImage
  Created on 2013/05/28 by Afrael Ortiz
  Grabs the content of a Windows Control and returns its bitmap image
  -- "do whatever you want with this" license --
*/

public static Bitmap GrabControlBitmapImage(Control control)
{
    var controlBounds = control.Bounds;
    using (var bitmap = new Bitmap(controlBounds.Width, controlBounds.Height))
    {
        using (var g = Graphics.FromImage(bitmap))
        {
            var controlLocation = control.PointToScreen(Point.Empty);
            g.CopyFromScreen(controlLocation, Point.Empty, controlBounds.Size);
        }
        return new Bitmap(bitmap);
    }            
}