实现“查找指定目录下所有文件”功能的程序代码。其采用了递归编程思想，简单实用，可在此基础上从事其他文件管理开发。-The realization of the　Find all files under specified directory　feature of program code. Its use of recursive programming ideas, simple and practical, may be on this basis to engage in other document management development.