C#程序源码。程序后台运行时，一旦有U盘插入就可以自动复制U盘内容到制定目录，快捷且隐蔽，具有一定的实用性。(C# program source code. When the program is running in the background, once the U disk is inserted, the contents of the U disk can be automatically copied to the directory, which is fast and hidd