将数据库中二进制文件，保存到本地磁盘或用网页方式下载

using System;















using System.Collections.Generic;















using System.Text;















using System.Data;















using System.Data.SqlClient;















using System.IO;































namespace ConsoleApplication2















{















    class Program















    {















        //把文件写入数据库















        public void add(string pathName)















        {















            FileStream fs = new FileStream(pathName, FileMode.Open, FileAccess.Read);















            byte[] buffByte = new byte[fs.Length];















            fs.Read(buffByte, 0, (int)fs.Length);















            fs.Close();















            fs = null;















            SqlConnection conn = new SqlConnection(@"data source=test;uid=sa;pwd=test;database=test");















            string sqlstr = @"Insert into table1(doc) values(@img)";















            SqlCommand cmd = new SqlCommand();















            cmd.CommandType = CommandType.Text;















            cmd.CommandText = sqlstr;















            cmd.Connection = conn;















            cmd.Parameters.Add("@img", System.Data.SqlDbType.Image);















            cmd.Parameters[0].Value = buffByte;















            conn.Open();















            cmd.ExecuteNonQuery();















            conn.Close();















            buffByte = null;































        }















        //从数据库读出文件















        public void save(string fileName)















        {















            SqlConnection conn = new SqlConnection(@"data source=test;uid=sa;pwd=test;database=test");















            conn.Open();















            SqlCommand cmd = new SqlCommand("select top 1 doc from table1", conn);















            SqlDataReader reader = cmd.ExecuteReader();















            byte[] buffByte = null;















            if (reader.Read())















            {















                buffByte = (byte[])reader[0];















            }















            reader.Close();















            conn.Close();















            FileStream fs;















            FileInfo fi = new FileInfo(fileName);















            fs = fi.OpenWrite();















            fs.Write(buffByte, 0, buffByte.Length);















            fs.Close();















        }















        static void Main(string[] args)















        {















            Program p = new Program();















            p.add(@"C:/test.doc");















            p.save(@"C:/test1.doc");















        }















    }















} 















//bs保存文件：







protected void downloadFile(string strYYBH)







    {







        SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["LIMSConnectionString"].ToString());







        conn.Open();







        SqlCommand cmd = new SqlCommand("select top 1 F_file,F_fileName from FileDoc where F_YYBH='" + strYYBH.ToString().Trim() + "'", conn);







        SqlDataReader reader = cmd.ExecuteReader();







        byte[] buffByte = null;







        string fileName = string.Empty;







        if (reader.Read())







        {







            buffByte = (byte[])reader[0];







            fileName = reader[1].ToString();







        }







        reader.Close();







        conn.Close();















        Response.ContentType = "application/octet-stream/unknow";







        Response.AddHeader("Content-Disposition", "attachment;   filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));







        this.Response.Clear();







        System.IO.Stream fs = this.Response.OutputStream;







        fs.Write(buffByte, 0, buffByte.Length);







        fs.Close();















        this.Response.End();







    }