• [转][html]大文件下载


    上面代码来自微软,用于下载大文件。

    下面代码来自 http://www.cnblogs.com/smile-wei/p/4159213.html

    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 = "DownloadFileName";
    
    // 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();
        }
    }
    protected void Btn_down_Click(object sender, EventArgs e)
        {
            if (ckl_ck.Items.Count > 0)
            {
                List<string> listFJ = new List<string>();//保存附件路径
                List<string> listFJName = new List<string>();//保存附件名字
                for (int i = 0; i < ckl_ck.Items.Count; i++)
                {
                    if (ckl_ck.Items[i].Selected)
                    {
                        listFJ.Add(Server.MapPath("Resource/Help/") + ckl_ck.Items[i].Text);
                        listFJName.Add(ckl_ck.Items[i].Text);
                    }
    
                }
                string time = DateTime.Now.Ticks.ToString();
                ZipFileMain(listFJ.ToArray(), listFJName.ToArray(), Server.MapPath("Resource/Help/" + time + ".zip"), 9);//压缩文件
                DownloadFile(Server.UrlEncode("附件.zip"), Server.MapPath("Resource/Help/" + time + ".zip"));//下载文件
            }
        }
        private void DownloadFile(string fileName, string filePath)
        {
            FileInfo fileInfo = new FileInfo(filePath);
            Response.Clear();
            Response.ClearContent();
            Response.ClearHeaders();
            Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
            Response.AddHeader("Content-Length", fileInfo.Length.ToString());
            Response.AddHeader("Content-Transfer-Encoding", "binary");
            Response.ContentType = "application/octet-stream";
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            Response.WriteFile(fileInfo.FullName);
            Response.Flush();
            File.Delete(filePath);//删除已下载文件
            Response.End();
        }
    
        /// <summary>
        /// 压缩文件
        /// </summary>
        /// <param name="fileName">要压缩的所有文件(完全路径)</param>
        /// <param name="fileName">文件名称</param>
        /// <param name="name">压缩后文件路径</param>
        /// <param name="Level">压缩级别</param>
        public void ZipFileMain(string[] filenames, string[] fileName, string name, int Level)
        {
            ZipOutputStream s = new ZipOutputStream(File.Create(name));
            Crc32 crc = new Crc32();
            //压缩级别
            s.SetLevel(Level); // 0 - store only to 9 - means best compression
            try
            {
                int m = 0;
                foreach (string file in filenames)
                {
                    //打开压缩文件
                    FileStream fs = File.OpenRead(file);//文件地址
                    byte[] buffer = new byte[fs.Length];
                    fs.Read(buffer, 0, buffer.Length);
                    //建立压缩实体
                    ZipEntry entry = new ZipEntry(fileName[m].ToString());//原文件名
                    //时间
                    entry.DateTime = DateTime.Now;
                    //空间大小
                    entry.Size = fs.Length;
                    fs.Close();
                    crc.Reset();
                    crc.Update(buffer);
                    entry.Crc = crc.Value;
                    s.PutNextEntry(entry);
                    s.Write(buffer, 0, buffer.Length);
                    m++;
                }
            }
            catch
            {
                throw;
            }
            finally
            {
                s.Finish();
                s.Close();
            }
        }
  • 相关阅读:
    设计模式之工厂模式
    东方通 部署项目 报错 内存溢出解决
    java8提取对象集合中的一项属性
    vue 函数节流
    ALINK(三十一):特征工程(十)特征选择(二)卡方选择器 (ChiSqSelectorBatchOp)
    ALINK(三十):特征工程(九)特征选择(一)主成分分析(PcaTrainBatchOp/PcaPredictBatchOp)
    ALINK(二十九):特征工程(八)特征组合与交叉(三)Hash Cross特征 (HashCrossFeatureBatchOp)
    ALINK(二十八):特征工程(七)特征组合与交叉(二)Cross特征预测/训练 (CrossFeaturePredictBatchOp)
    ALINK(二十七):特征工程(六)特征组合与交叉(特征组合也叫特征交叉)(一)
    ALINK(二十六):特征工程(五)特征离散化(五)二值化 (BinarizerBatchOp)
  • 原文地址:https://www.cnblogs.com/z5337/p/5121084.html
Copyright © 2020-2023  润新知