在http-context响应C#中分块下载文件

Question

我有以下情况。

客户端向 Server-1 发送文件下载请求 Server-1 向 Server-2 发送文件请求。

为了完成这项工作，我需要创建一种机制，一旦客户端向 Server-1 发送请求，Server-1 将向 Server-2 请求，Server-2 将文件作为响应输出流以块的形式发送。 Server-1 会不断地向客户端浏览器发送这个文件块，因为它会不断地从 server-2 接收。

我已经完成了如下代码，理论上它看起来不错，但仍然无法正常工作。 它没有在客户端浏览器中下载整个文件，似乎最后一个块没有传输到 Server-1 或者它没有从 Server-1 下载到客户端浏览器

Server-1 代码（客户端请求文件下载的地方）

    private void ProccesBufferedResponse(HttpWebRequest webRequest, HttpContext context)
    {
        char[] responseChars = null;
        byte[] buffer = null;

        if (webRequest == null)
            logger.Error("Request string is null for Perfios Docs Download at ProccesBufferedResponse()");

        context.Response.Buffer = false;
        context.Response.BufferOutput = false;
        try
        {

            WebResponse webResponse = webRequest.GetResponse();
            context.Response.ContentType = "application/pdf";
            context.Response.AddHeader("Content-disposition", webResponse.Headers["Content-disposition"]);

            StreamReader responseStream = new StreamReader(webResponse.GetResponseStream());
            while (!responseStream.EndOfStream)
            {
                responseChars = new char[responseStream.ToString().ToCharArray().Length];
                responseStream.Read(responseChars, 0, responseChars.Length);
                buffer = Encoding.ASCII.GetBytes(responseChars);

                context.Response.Clear();
                context.Response.OutputStream.Write(buffer, 0, buffer.Length);
                context.Response.Flush();

            }

        }
        catch (Exception ex)
        {
            throw;
        }
        finally
        {
            context.Response.Flush();
            context.Response.End();
        }
    }

Server-2 代码（Server-1 将发送文件请求的位置）

    private void DownloadInstaPerfiosDoc(int CompanyID, string fileName, string Foldertype)
    {
        string folderPath;
        string FilePath;
        int chunkSize = 1024;
        int startIndex = 0;
        int endIndex = 0;
        int length = 0;
        byte[] bytes = null;
        DirectoryInfo dir;

        folderPath = GetDocumentDirectory(CompanyID, Foldertype);
        FilePath = folderPath + "\\" + fileName;
        dir = new DirectoryInfo(folderPath);
        HttpContext.Current.Response.Buffer = false;
        HttpContext.Current.Response.BufferOutput = false;

        if (dir.Exists && dir.GetFiles().Length > 0)
        {
            foreach (var file in dir.GetFiles(fileName))
            {
                FilePath = folderPath + "\\" + file.Name;
                FileStream fsReader = new FileStream(FilePath, FileMode.Open, FileAccess.Read);

                HttpContext.Current.Response.ContentType = "application/pdf";
                HttpContext.Current.Response.AddHeader("Content-disposition", string.Format("attachment; filename = \"{0}\"", fileName));

                int totalChunks = (int)Math.Ceiling((double)fsReader.Length / chunkSize);
                for (int i = 0; i < totalChunks; i++)
                {
                    startIndex = i * chunkSize;

                    if (startIndex + chunkSize > fsReader.Length)
                        endIndex = (int)fsReader.Length;
                    else
                        endIndex = startIndex + chunkSize;

                    length = (int)endIndex - startIndex;
                    bytes = new byte[length];
                    fsReader.Read(bytes, 0, bytes.Length);
                    HttpContext.Current.Response.Clear();
                    HttpContext.Current.Response.OutputStream.Write(bytes, 0, bytes.Length);
                    HttpContext.Current.Response.Flush();
                }
            }
        }
    }

请帮我解决这个问题。

Answer 1

这是可能的和可行的。我会给出一个伪程序让你理解整体思路。

服务器1

download action gets hit
create a request to server2
get the response stream of your server2 request
read the response stream in desired chunk sizes until it's consumed completely
write each chunk (as soon as you read) to current response stream

服务器2

download action gets hit
write your stream onto your current response stream however you like