关键代码：

        /// <summary>        /// 设置图片节点的背景色        /// 说明：在CustomDrawNodeImages事件中使用        /// </summary>        /// <param name="tree">TreeList</param>        /// <param name="e">CustomDrawNodeImagesEventArgs</param>        /// <param name="builderBackColorHandler">委托</param>        public static void CustomImageNodeBackColor(this TreeList tree, CustomDrawNodeImagesEventArgs e, Func<TreeListNode, Color> builderBackColorHandler)        {            TreeListNode _node = e.Node;            Color _backColor = builderBackColorHandler(_node);            e.Graphics.FillRectangle(new SolidBrush(_backColor), e.Bounds);        }

使用代码：

        private void tlLHData_CustomDrawNodeImages(object sender, CustomDrawNodeImagesEventArgs e)        {            try            {                tlLHData.CustomImageNodeBackColor(e, node =>                {                    string _cabId = node.GetKeyID();                    CCabInfo _cabInfo = LHDBHelper.GetCabInfo(_cabId);                    if (_cabInfo != null)                    {                        return _cabInfo.CtuOnlineStatus == 1 ? Color.White : Color.LightGray;                    }                    return Color.White;                });            }            catch (Exception)            {            }        }

<style type="text/css">.csharpcode, .csharpcode pre{ font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/}.csharpcode pre { margin: 0em; }.csharpcode .rem { color: #008000; }.csharpcode .kwrd { color: #0000ff; }.csharpcode .str { color: #006080; }.csharpcode .op { color: #0000c0; }.csharpcode .preproc { color: #cc6633; }.csharpcode .asp { background-color: #ffff00; }.csharpcode .html { color: #800000; }.csharpcode .attr { color: #ff0000; }.csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em;}.csharpcode .lnum { color: #606060; }</style>代码效果