public BindingTreeView()
{
InitializeComponent();
// if some but not all nodes have icons, then the treeview control pulls the first icon from the list
// to fix this problem, we'll explicitly add a dummy transparent icon for use by nodes without icons
Bitmap blankIcon = new Bitmap(1, 1);
blankIcon.SetPixel(0, 0, Color.Transparent);
_imageList.Images.Add(string.Empty, blankIcon);
this.RebuildStateImageList();
}