B1T ZeR0 - Professional Profile

/// <summary>
/// Gets the Scrollbar for the current list box
/// </summary>
/// <param name="listBox">The ListBox to get he scrollbar from.</param>
/// <returns>ScrollBar</returns>
public static ScrollBar GetScrollBar(this ListBox listBox)
{
   //Need to start moving through the ListBox Visual Tree.
   //The ListBox only has one child, the Border Element
   Border scroll_border = System.Windows.Media.VisualTreeHelper.GetChild(listBox, 0) as Border;
   //Confirm we got the border element.
   if (scroll_border is Border)
   {
       //Need to get the next child, the ScrollViewer
       ScrollViewer scroll = scroll_border.Child as ScrollViewer;
       if (scroll is ScrollViewer)
       {
           //The ScrollViewer only has 1 Child as well.  Lets get it.
           Grid lbGrid = System.Windows.Media.VisualTreeHelper.GetChild(scroll, 0) as Grid;
           if (lbGrid is Grid)
           {
               //The Grid has four child elements
               /* Element 0 = Rectangle
                * Element 1 = ScrollContentPresenter
                * Element 2 = Vertical ScrollBar <- This is the one we want
                * Element 3 = Horizontal ScrollBar */
               ScrollBar sBar = System.Windows.Media.VisualTreeHelper.GetChild(lbGrid, 2) as ScrollBar;
               if (sBar is ScrollBar)
               {
                   return sBar;
               }
               else
               {
                   return null;
               }
           }
           else
           {
               return null;
           }
       }
       else
       {
           return null;
       }
   }
   else
   {
       return null;
   }
}

using System.Windows.Media;
using System.Windows.Controls.Primitives;

//This will call the extension method and return the associated vertical scrollbar for the listbox.
ScrollBar sBar = lstSample.GetScrollBar();
if (sBar != null)
{
     sBar.Background = new LinearGradientBrush(Colors.LightGreen, Colors.Blue, 50);
}