文件和字节流的相互转换

1、读取文件，并转换为字节流 

FileStream fs = new FileStream(filename, FileMode.Open, FileAccess.Read);
            byte[] infbytes = new byte[(int)fs.Length];
            fs.Read(infbytes, 0, infbytes.Length);
            fs.Close();

            return infbytes;

 2、将字节流写入文件 

FileStream fs = new FileStream("D:inf.dlv", FileMode.Create, FileAccess.Write);
            fs.Write(inf, 0, inf.Length);
            fs.Close();