二进制流转化为文件 怎么从数据中读取

string filePath = @"D:\";
string fileName = @"1.txt";
FileStream fs = new FileStream(filePath + fileName, FileMode.Open);
byte[] bytes = new byte[(int)fs.Length];
fs.Read(bytes, 0, bytes.Length);
fs.Close();
Response.Charset = "UTF-8";
Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8");
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment;filename=" + Server.UrlEncode(fileName));
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();

        return new EmptyResult();

http://www.cnblogs.com/ldp615/archive/2010/09/17/asp-net-mvc-file-result.html

数据库字段存二进制数组，然后读取出来转换