说明：  使用VB.NET编程语言在Visual Basic.NET 2003的平台下自己动手设计开发一款文件加密软件，采用DES加密算法，能实现对各种类型的文件进行加密和解密是关键之处，主要要把这个做完善。
(use VB.NET programming language in Visual Basic.NET 2003 platform personally developed an encryption software documentation using DES encryption algorithm, can be achieved for all types of document encryption and decryption is the key word, we want to do perfect.)