private void downLoad(string id)

        {

            string fileName = Page.Request.PhysicalApplicationPath + "SystemManage\\SysFile\\" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".zip";

            OracleConnection conn = null;

            string connString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString();

            using (conn = new OracleConnection(connString))

            {

                try

                {

                    conn.Open();

                    OracleCommand cmd = conn.CreateCommand();

 

                    // 利用事务处理（必须）

                    OracleTransaction transaction = cmd.Connection.BeginTransaction();

                    cmd.Transaction = transaction;

                    // 根据查询语句获取对应的上传文件的BLOB信息

                    string sql = "select 上传文件 from 文件上传表 where 编号 = " + id;

                    cmd.CommandText = sql;

                    OracleDataReader dr = cmd.ExecuteReader();

                    dr.Read();

                    OracleLob tempLob = dr.GetOracleLob(0);

                    dr.Close();

                    // 读取 BLOB 中数据，写入到文件中

                    FileStream fs = new FileStream(fileName, FileMode.Create);

                    int length = 1048576;

                    byte[] Buffer = new byte[length];

                    int i;

                    while ((i = tempLob.Read(Buffer, 0, length)) > 0)

                    {

                        fs.Write(Buffer, 0, i);

                    }

                    fs.Close();

                    tempLob.Clone();

                    cmd.Parameters.Clear();

                    // 提交事务

                    transaction.Commit();

                    DownloadFile(fileName);

                    File.Delete(fileName);

                }

                catch (Exception ex)

                {

                    throw ex;

                }

                finally

                {

                    conn.Close();

                }

            }

        }

 

 

 

   /// <summary>

        /// 下载文件

        /// </summary>

        /// <param name="fileName">文件名称</param>

        public void DownloadFile(string fileName)

        {

            try

            {

                //by K 2010-08-13 下载超过100M的附件  需要用以下方法

                System.IO.Stream iStream = null;

 

                // Buffer to read 10K bytes in chunk:

                byte[] buffer = new Byte[10000];

                // Length of the file:

                int length;

                // Total bytes to read:

                long dataToRead;

                // Identify the file to download including its path.

                string filepath = fileName;

                // Identify the file name.

                string filename = System.IO.Path.GetFileName(filepath);

                try

                {

                    // Open the file.

                    iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open,

                    System.IO.FileAccess.Read, System.IO.FileShare.Read);

                    // Total bytes to read:

                    dataToRead = iStream.Length;

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

                    Response.AddHeader("Content-Disposition", "attachment; filename=" + filename);

                    // Read the bytes.

                    while (dataToRead > 0)

                    {

                        // Verify that the client is connected.

                        if (Response.IsClientConnected)

                        {

                            // Read the data in buffer.

                            length = iStream.Read(buffer, 0, 10000);

                            // Write the data to the current output stream.

                            Response.OutputStream.Write(buffer, 0, length);

                            // Flush the data to the HTML output.

                            Response.Flush();

                            buffer = new Byte[10000];

                            dataToRead = dataToRead - length;

                        }

                        else

                        {

                            //prevent infinite loop if user disconnects

                            dataToRead = -1;

                        }

                    }

                }

                catch (Exception ex)

                {

                    // Trap the error, if any.

                    Response.Write("Error : " + ex.Message);

                }

                finally

                {

                    if (iStream != null)

                    {

                        //Close the file.

                        iStream.Close();

                    }

                }

               

            }

            catch (Exception ex)

            {

                AppCode.CommonFunc.AlertScript("对不起，文件下载时出现错误！");

            }

        }