/// <summary>/// 普通下载/// </summary>public void Download(){string fileName = "下载测试test.txt";string filePath = Server.MapPath("/File/test.txt");System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);if (fileInfo.Exists == true){const long ChunkSize = 10240;byte[] buffer = new byte[ChunkSize];Response.Clear();System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);long dataLengthToRead = iStream.Length;//获取下载的文件总大小 Response.ContentEncoding = Encoding.UTF8;Response.ContentType = "application/octet-stream";Response.AddHeader("Content-Disposition", "attachment; filename=" + fileName);while (dataLengthToRead > 0 && Response.IsClientConnected){Thread.Sleep(100);int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小 Response.OutputStream.Write(buffer, 0, lengthRead);Response.Flush();dataLengthToRead -= lengthRead;}Response.Close();}}

        /// <summary>/// FastDFS下载文件，断点续传/// </summary>/// <returns></returns>public bool DownloadByFDFS(){string group_name = "group1";string remote_filename = "M00/00/00/CgEG1FlWChOEHXNFAAAAAEFinIM178.txt";string fileName = "测试.txt";long length = 2878186;long speed = 1024 * 100;bool ret = true;try{#region--验证：HttpMethod，请求的文件是否存在switch (Request.HttpMethod.ToUpper()){ //目前只支持GET和HEAD方法case "GET":case "HEAD":break;default:Response.StatusCode = 501;return false;}#endregion#region 定义局部变量long startBytes = 0;int packSize = 1024 * 10; //分块读取，每块10K byteslong fileLength = length;// myFile.Length;int sleep = (int)Math.Ceiling(1000.0 * packSize / speed);//毫秒数：读取下一数据块的时间间隔string lastUpdateTiemStr = "2017-07-18 11:57:54";string eTag = HttpUtility.UrlEncode(fileName, Encoding.UTF8) + lastUpdateTiemStr;//便于恢复下载时提取请求头;#endregion#region--验证：文件是否太大，是否是续传，且在上次被请求的日期之后是否被修改过--------------//if (myFile.Length > Int32.MaxValue)//{//-------文件太大了-------//    Response.StatusCode = 413;//请求实体太大//    return false;//}if (Request.Headers["If-Range"] != null)//对应响应头ETag：文件名+文件最后修改时间
                {//----------上次被请求的日期之后被修改过--------------if (Request.Headers["If-Range"].Replace("\"", "") != eTag){//文件修改过Response.StatusCode = 412;//预处理失败return false;}}#endregiontry{#region -------添加重要响应头、解析请求头、相关验证-------------------Response.Clear();Response.Buffer = false;//Response.AddHeader("Content-MD5", GetMD5Hash(myFile));//用于验证文件Response.AddHeader("Accept-Ranges", "bytes");//重要：续传必须Response.AppendHeader("ETag", "\"" + eTag + "\"");//重要：续传必须Response.AppendHeader("Last-Modified", lastUpdateTiemStr);//把最后修改日期写入响应                Response.ContentType = "application/octet-stream";//MIME类型：匹配任意文件类型Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);//s HttpUtility.UrlEncode(fileName, Encoding.UTF8).Replace("+", "%20"));
Response.AddHeader("Connection", "Keep-Alive");Response.ContentEncoding = Encoding.UTF8;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。初始下载时默认为200string[] range = Request.Headers["Range"].Split(new char[] { '=', '-' });//"bytes=1474560-"startBytes = Convert.ToInt64(range[1]);//已经下载的字节数，即本次下载的开始位置  if (startBytes < 0 || startBytes >= fileLength){//无效的起始位置return false;}}Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());if (startBytes > 0){//------如果是续传请求，告诉客户端本次的开始字节数，总长度，以便客户端将续传数据追加到startBytes位置后----------Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength));}#endregion#region -------向客户端发送数据块-------------------//binaryReader.BaseStream.Seek(startBytes, SeekOrigin.Begin);int maxCount = (int)Math.Ceiling((fileLength - startBytes + 0.0) / packSize);//分块下载，剩余部分可分成的块数for (int i = 0; i < maxCount && Response.IsClientConnected; i++){//客户端中断连接，则暂停if (fileLength - startBytes < packSize)packSize = 0;byte[] fdfs = client.download_file(group_name, remote_filename, startBytes, packSize);Response.BinaryWrite(fdfs);Response.Flush();startBytes = startBytes + packSize;if (sleep > 1) Thread.Sleep(sleep);}#endregion}catch{ret = false;}finally{}}catch{ret = false;}return ret;}

        public string Upload(HttpPostedFileBase file){string group = "";string path = "";string tempPath = Server.MapPath("~/File/temp.txt");byte[] buffer = new byte[file.ContentLength];System.IO.Stream fs = (System.IO.Stream)file.InputStream;fs.Read(buffer, 0, file.ContentLength);NameValuePair[] meta_list = new NameValuePair[4];meta_list[0] = new NameValuePair("width", "800");meta_list[1] = new NameValuePair("heigth", "600");meta_list[2] = new NameValuePair("bgcolor", "#FFFFFF");meta_list[3] = new NameValuePair("author", "Mike");if (Request.Params["chunk"] == "0" || Request.Params["chunk"] == null){string ext = Path.GetExtension(file.FileName).Replace(".", "");//fastdfs上传var results = client.upload_appender_file(buffer, ext, meta_list);group = results[0];path = results[1];//临时存储group、pathStreamWriter sw = new StreamWriter(tempPath, false);sw.WriteLine(group);sw.WriteLine(path);sw.Close();}else{if (System.IO.File.Exists(tempPath)){StreamReader sr = new StreamReader(tempPath);int i = 0;string strReadline = string.Empty;//读取group、pathwhile ((strReadline = sr.ReadLine()) != null){if (i == 0)group = strReadline;else if (i == 1)path = strReadline;i++;}sr.Close();}//文件续传，fastdfs追加上传var flag = client.append_file(group, path, buffer);}return "{\"data\":{\"chunked\" : true, \"ext\" : \"exe\"}}";}public string GetMaxChunk(string md5){//根据实际存储介质返回文件上传终止的段return "{\"data\":0}";}

        /// <summary>/// PushStreamContent 推送/// FDFS文件，断点续传/// </summary>/// <returns></returns>public HttpResponseMessage GetFileFDFS(){HttpResponseMessage response = new HttpResponseMessage();if (Request.Headers.IfRange != null && Request.Headers.IfRange.EntityTag.ToString().Replace("\"", "") != NowTime){response.StatusCode = HttpStatusCode.PreconditionFailed;return response;}string group_name = "group1";string remote_filename = "M00/00/00/CgEG1FlWChOEHXNFAAAAAEFinIM178.txt";string fileName = "测试.txt";long fileLength = 2878186;long speed = 1024 * 100;long packSize = 1024 * 10;int sleep = (int)Math.Ceiling(1000.0 * packSize / speed);//毫秒数：读取下一数据块的时间间隔ContentInfo contentInfo = GetContentInfoFromRequest(this.Request, fileLength);Action<Stream, HttpContent, TransportContext> pushContentAction = (outputStream, content, context) =>{try{int length = Convert.ToInt32((fileLength - 1) - contentInfo.From) + 1;while (length > 0 && packSize > 0){byte[] fdfs = client.download_file(group_name, remote_filename, contentInfo.From, Math.Min(length, packSize));outputStream.Write(fdfs, 0, fdfs.Length);contentInfo.From = contentInfo.From + fdfs.Length;length -= fdfs.Length;if (sleep > 1) Thread.Sleep(sleep);}//int maxCount = (int)Math.Ceiling((fileLength - contentInfo.From + 0.0) / packSize);//分块下载，剩余部分可分成的块数//for (int i = 0; i < maxCount && HttpContext.Current.Response.IsClientConnected; i++)//{//    if (fileLength - contentInfo.From < packSize)//        packSize = 0;//    byte[] fdfs = client.download_file(group_name, remote_filename, contentInfo.From, packSize);//    outputStream.Write(fdfs, 0, fdfs.Length);//    contentInfo.From = contentInfo.From + fdfs.Length;//    if (sleep > 1) Thread.Sleep(sleep);//}
                }catch (HttpException ex){throw ex;}finally{outputStream.Close();}};response.Content = new PushStreamContent(pushContentAction, new MediaTypeHeaderValue(MimeType));//response.Content = new PushStreamContent(pushContentAction);
            SetResponseHeaders(response, contentInfo, fileLength, fileName);return response;}