C# TreeView递归遍历方法

 /**
         * 遍历树种的值步骤
         * <summary>
         *      1.查找TreeView控件是否有指定值的节点
         * </summary>
         * <param name="tvControl">TreeView控件</param>
         * <param name="strValue">指定节点值</param> 
         * <returns></returns>
         **/
        public static TreeNode FindNode(TreeView tvControl, string strValue)
        {
            TreeNode tnRet=null;
            foreach (TreeNode tn in tvControl.Nodes)
            {
                tnRet = FindNode(tn, strValue);
                if (tnRet != null) break;
            }
            return tnRet;
        }

        /**
         * 遍历树种的值步骤
         * <summary>
         *      2.查找当前节点下是否有指定值的节点
         * </summary>
         * <param name="tnParent">当前节点</param>
         * <param name="strValue">指定节点值</param> 
         * <returns>TreeNode</returns>
         **/
        public static TreeNode FindNode(TreeNode tnParent, string strValue)
        {
            if(tnParent==null) return null;
            if(tnParent.Value==strValue) return tnParent;
            TreeNode tnRet = null;
            TreeNode tnTemp = null;
            foreach(TreeNode tn in tnParent.ChildNodes)
            {
                tnTemp = FindNode(tn, strValue);
                if(tnTemp !=null && tnTemp.Value==strValue)
                {
                    tnRet = tnTemp;
                    break;
                }
            }
            return tnRet;
        }