实现多线程断点续传下载大文件代码,Asp.NET代码库,德仔网

代码语言
代码分类
【Asp.NET】实现多线程断点续传下载大文件
作者: / 发布于2019/11/4/ 1544
/// <summary>
        /// 下载的方法
        /// </summary>
        /// <param name="filepath">下载文件的路径</param>
 
       public void Reget(string filepath)
        {
            System.IO.Stream iStream = null;
 
            // 分块读取，每块10K bytes 
            byte[] buffer = new Byte[10240];
 
            //文件的大小
            int length;
 
            // 文件的字节数
            long dataToRead;
 
           // 得到文件名
            string filename = System.IO.Path.GetFileName(filepath);
 
            try
            {
                Response.Clear();
                Response.ClearHeaders();
                //打开文件
                iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open,
                    System.IO.FileAccess.Read, System.IO.FileShare.Read);
 
                // 总字节
                dataToRead = iStream.Length;
 
                long p = 0;
                if (Request.Headers["Range"] != null)
                {
                    //如果是续传请求，则获取续传的起始位置，即已经下载到客户端的字节数
                    Response.StatusCode = 206; //重要：续传必须，表示局部范围响应。
                    p = long.Parse(Request.Headers["Range"].Replace("bytes=", "").Replace("-", ""));
                }
                if (p != 0)
                {
                    //不是从最开始下载,
                    //响应的格式是:Content-Range: bytes [文件块的开始字节]-[文件的总大小 - 1]/[文件的总大小]
                    Response.AddHeader("Content-Range", "bytes " + p.ToString() + "-" + ((long)(dataToRead - 1)).ToString() + "/" + dataToRead.ToString());
                }
                Response.AddHeader("Connection", "Keep-Alive");
                Response.AddHeader("Content-Length", ((long)(dataToRead - p)).ToString());
                Response.ContentType = "application/octet-stream";   //MIME类型：匹配任意文件类型 
                Response.AddHeader("Content-Disposition", "attachment; filename=" + System.Web.HttpUtility.UrlEncode(Request.ContentEncoding.GetBytes(filename)));
 
                iStream.Position = p;
                dataToRead = dataToRead - p;
                // 读字节
                while (dataToRead > 0)
                {
                    //确认客户端连接
                    if (Response.IsClientConnected)
                    {
                        // Read the data in buffer.
                        length = iStream.Read(buffer, 0, 10240);
 
                        // 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[10240];
                        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)
                {
                    //关闭流
                    iStream.Close();
                }
                Response.End();
            }
        }
试试其它关键字
同语言下
可能有用的
贡献的其它代码Label