利用Socket套接字创建基于对话框类的FTP工具。主要功能是在网络上的FTP服务器上，实现单线程下载，能够实现文件上传功能。-use Socket created based on the type dialog FTP tools. Its main function is on the network FTP server, the thread to achieve the download, upload documents to achieve functional.

很经典的ftp服务器实现，实现为一个类，附带一个命令行的demo， 可跨平台-Classic implementation of the ftp server, a type of implementation, with a command-line demo, can be cross-platform