// 得到用户要上传的文件名

             string  strFilePathName  =  loFile.PostedFile.FileName;

             string  strFileName  =  Path.GetFileName(strFilePathName);

             int  FileLength  =  loFile.PostedFile.ContentLength;

             if (FileLength <= 0 )

                 return ;

             try

             {

//上传文件

                Byte[] FileByteArray = new Byte[FileLength]; //图象文件临时储存Byte数组

                Stream StreamObject = loFile.PostedFile.InputStream; //建立数据流对像

                //读取图象文件数据，FileByteArray为数据储存体，0为数据指针位置、FileLnegth为数据长度

                StreamObject.Read(FileByteArray,0,FileLength); 

                //建立SQL Server链接

                string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];

                SqlConnection Con = new SqlConnection(strCon);

                String SqlCmd = "INSERT INTO ImageStore (ImageData, ImageContentType, ImageDescription, ImageSize) VALUES (@Image, @ContentType, @ImageDescription, @ImageSize)";

                SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);

                CmdObj.Parameters.Add("@Image",SqlDbType.Binary, FileLength).Value = FileByteArray;

                CmdObj.Parameters.Add("@ContentType", SqlDbType.VarChar,50).Value = loFile.PostedFile.ContentType; //记录文件类型

                //把其它单表数据记录上传

                CmdObj.Parameters.Add("@ImageDescription", SqlDbType.VarChar,200).Value = tbDescription.Text;

                //记录文件长度，读取时使用

                CmdObj.Parameters.Add("@ImageSize", SqlDbType.BigInt,8).Value = FileLength;

                Con.Open();

                CmdObj.ExecuteNonQuery(); 

                Con.Close();

                //跳转页面

                Response.Redirect("ShowAll.aspx");

            }

             catch

             {

            }

int  ImgID  =  Convert.ToInt32(Request.QueryString[ " ID " ]);  // ID为图片ID 

             // 建立数据库链接

             string  strCon  =  System.Configuration.ConfigurationSettings.AppSettings[ " DSN " ];

            SqlConnection Con  =   new  SqlConnection(strCon);

            String SqlCmd  =   " SELECT * FROM ImageStore WHERE ImageID = @ImageID " ;

            SqlCommand CmdObj  =   new  SqlCommand(SqlCmd, Con);

            CmdObj.Parameters.Add( " @ImageID " , SqlDbType.Int).Value  =  ImgID;

            Con.Open();

            SqlDataReader SqlReader  =  CmdObj.ExecuteReader();

            SqlReader.Read(); 

            Response.ContentType  =  ( string )SqlReader[ " ImageContentType " ]; // 设定输出文件类型

             // 输出图象文件二进制数制

            Response.OutputStream.Write(( byte [])SqlReader[ " ImageData " ],  0 , ( int )SqlReader[ " ImageSize " ]); 

            Response.End();

             // 也可以保存为图像

//             FileStream fs = new FileStream(@"C:\aa.BMP", FileMode.OpenOrCreate, FileAccess.Write);

//             fs.Write((byte[])SqlReader["ImageData"], 0,(int)SqlReader["ImageSize"]);

//             fs.Close();

            Con.Close();

出现提示框

string  strFile = " F:\\a.doc " ; // 路径根据实际情况而定

if ( ! System.IO.File.Exists(strFile))

    {

    Response.Write("<script language='javascript'>alert('对不起，文件不存在！');</script>");

    return;

   }

   Response.Clear();

   Response.ClearHeaders();

   Response.Charset  =   " GB2312 " ;

   Response.ContentEncoding  = System.Text.Encoding.UTF8;

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

   FileInfo fi = new  FileInfo(strFile);

   Response.AddHeader( " Content-Disposition " , " attachment;  filename= "    +   HttpUtility.UrlEncode(fi.Name)) ;

   Response.AddHeader( " Content-Length " ,fi.Length.ToString());

    byte [] tmpbyte = new   byte [ 1024 * 8 ];

   FileStream fs = fi.OpenRead();

    int  count;

    while ((count = fs.Read(tmpbyte, 0 ,tmpbyte.Length)) > 0 )

    {

    Response.BinaryWrite(tmpbyte);

    Response.Flush();

   }

   fs.Close();   

   Response.End();

直接在浏览器中打开

    string  strFile = " F:\\a.doc " ; // 路径根据实际情况而定

   Response.Clear();

   Response.ClearHeaders();

   Response.Charset  =   " GB2312 " ;

   Response.ContentEncoding  = System.Text.Encoding.UTF8;

   Response.ContentType  =   " application/msword " ; 

   Response.WriteFile(strFile);

For example:

Response.ContentType  =   " image/jpeg " ;Response.AppendHeader( " Content-Disposition " , " attachment; filename=SailBig.jpg " );Response.TransmitFile( Server.MapPath( " ~/images/sailbig.jpg " ) );Response.End();