遍历文件夹并建成目录树
......................\FileTree.clw
......................\FileTree.cpp
......................\FileTree.dsp
......................\FileTree.dsw
......................\FileTree.h
......................\FileTree.rc
......................\FileTreeDlg.cpp
......................\FileTreeDlg.h
......................\ReadMe.txt
......................\res

......................\...\FileTree.rc2
......................\...\kebiao.ico
......................\Resource.h
......................\StdAfx.cpp
......................\StdAfx.h
......................\开源盛世ReadMe.txt
......................\成绩表
......................\......\C语言
......................\......\.....\计算机01－1.txt
......................\......\.....\计算机01－2.txt
......................\......\.....\计算机01－3.txt
......................\......\VC程序设计
......................\......\..........\信息
......................\......\..........\计算机
......................\......\..........\......\计算机01－1.txt
......................\......\..........\......\计算机01－2.txt
......................\......\..........\......\计算机01－3.txt
......................\......\..........\......\计算机01－4.txt
......................\......\..........\......\计算机01－5.txt
......................\......\..........\......\计算机01－6.txt
......................\......\数学
......................\......\....\计算机01－1.txt
......................\......\....\计算机01－2.txt
......................\......\....\计算机01－3.txt
......................\......\英语
......................\......\....\计算机01－1.txt
......................\......\....\计算机01－2.txt
......................\......\....\计算机01－3.txt
......................\......\计算机基础
......................\......\..........\计算机01－1.txt
......................\......\..........\计算机01－2.txt
......................\......\..........\计算机01－3.txt