关键代码：

        /// <summary>        /// 获取可视区域节点        /// </summary>        /// <param name="treeList">TreeList</param>        /// <param name="conditonHanlder">条件委托</param>        /// <returns>可视区域节点集合</returns>        public static List<TreeListNode> GetVisibleNodes(this TreeList treeList, Predicate<TreeListNode> conditonHanlder)        {            List<TreeListNode> _visibleNodes = new List<TreeListNode>();            RowsInfo _rowsInfo = treeList.ViewInfo.RowsInfo;            foreach (RowInfo ri in _rowsInfo.Rows)            {                TreeListNode _curNode = ri.Node;                if (conditonHanlder(_curNode))                {                    _visibleNodes.Add(_curNode);                }            }            return _visibleNodes;        }        /// <summary>        ///  获取可视区域节点        /// </summary>        /// <param name="treeList">TreeList</param>        /// <returns>可视区域节点集合</returns>        public static List<TreeListNode> GetVisibleNodes(this TreeList treeList)        {            return GetVisibleNodes(treeList, n => 1 == 1);        }

代码使用：

MessageBox.Show(tvwLamp.LHTree.GetVisibleNodes(n => n.GetNodeType() == NodeType.Cab).Count.ToString());

希望有所帮助！