程序分为发送端和接收端。首先在传输文件数据之前，发送端会把将装有文件名称和文件长度等 信息的数据包发送至接收端。接收端收到文件名称和文件长度信息后会创建好空白文件。接着开始传输 文件数据。-Program is divided into the sender and the receiver. First in a transmission file data before, the sender will put with the name of the document and fi