asp.net 获取指定文件夹下所有子目录及文件(树形)

                        }
                        Rn += _f + "│ ├";
                    }
                    Rn += fInfo.Name.ToString() + "</option>";
                }
                Rn = ListTreeShow(dirinfo, nLevel + 1, Rn, tplPath);


            }
            return Rn;
        }
        #endregion