程序代码：

        private TreeNode CreateDirNode(string fullPath)
        {
            /*检查Path是否存在*/
            if (Directory.Exists(fullPath))
            {
                DirectoryInfo currentDirPath = new DirectoryInfo(fullPath);
                TreeNode dirNode = new TreeNode(fullPath, 0, 0);

                if (currentDirPath.GetDirectories().Length >= 1)
                {
                    /*递归当前目录下的文件夹*/
                    foreach (DirectoryInfo dirInfo in currentDirPath.GetDirectories())
                    {
                        dirNode.Nodes.Add(CreateDirNode(dirInfo.FullName));
                    }
                }

                /*创建当前目录下所有的文件*/
                List<TreeNode> nodes = new List<TreeNode>();
                foreach (FileInfo fileInfo in currentDirPath.GetFiles())
                {
                    TreeNode trnd = new TreeNode(fileInfo.Name, 1, 1);
                    nodes.Add(trnd);
                }

                foreach (TreeNode tn in nodes)
                {
                    dirNode.Nodes.Add(tn);
                }

                return dirNode;
            }
            else
            {
                throw new Exception("Error! \"" + fullPath + "\" is not exisit!\r\n");
            }
        }
    }