winfrom 通过multipart/form-data方式 上传EXCEL文件，发生错误

Question

static void FileUpload(string m_fileNamePath, string wenjianmin)
{
string Boundary = "wojuedezhgexiangmushigekeng";

        //构造请求参数
        Dictionary<string, string> PostInfo = new Dictionary<string, string>();
        //PostInfo.Add("sequenceNo ", "A0002");
        //PostInfo.Add("type", "application/vnd.ms-excel");
        //PostInfo.Add("file", "");
        //PostInfo.Add("filename", wenjianmin);

        //构造POST请求体
        StringBuilder PostContent = new StringBuilder("--" + Boundary);
        byte[] ContentEnd = Encoding.UTF8.GetBytes("--" + Boundary + "--\r\n");//请求体末尾，后面会用到
                                                                               //组成普通参数信息
        foreach (KeyValuePair<string, string> item in PostInfo)
        {
            PostContent.Append("\r\n")
                    .Append("Content-Disposition: form-data; name=\"")
                    .Append(item.Key + "\"").Append("\r\n")
                    .Append("\r\n").Append(item.Value).Append("\r\n")
                    .Append("--").Append(Boundary);
        }
        //转换为二进制数组，后面会用到
        byte[] PostContentByte = Encoding.UTF8.GetBytes(PostContent.ToString());

        //文件信息
        byte[] UpdateFile = File2Bytes(m_fileNamePath);//转换为二进制
        StringBuilder FileContent = new StringBuilder();
        FileContent.Append("\r\n")
                .Append("Content-Disposition:form-data; name=\"")
                .Append("flie" + "\"; ")
                .Append("filename=\"")
                .Append(wenjianmin + "\"")
                .Append("\r\n")
                .Append("Content-Type: application/vnd.ms-excel")
                .Append("\r\n")
                .Append("\r\n");
        byte[] FileContentByte = Encoding.UTF8.GetBytes(FileContent.ToString());

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(m_address);
        request.Method = "POST";
        request.Timeout = 100000;
        //这里确定了分隔符是什么
        request.Headers.Add("Cookie", "JSESSIONID=19FCE6CF428E78732830248719E3836A");
        //request.Headers.Add("Accept-Encoding", " gzip, deflate");

        request.ContentType = "multipart/form-data;boundary=" + Boundary;
        //request.Cookie = "";
        //定义请求流
        Stream myRequestStream = request.GetRequestStream();
        myRequestStream.Write(PostContentByte, 0, PostContentByte.Length);//写入参数
        myRequestStream.Write(FileContentByte, 0, FileContentByte.Length);//写入文件信息
        myRequestStream.Write(UpdateFile, 0, UpdateFile.Length);//文件写入请求流中
        myRequestStream.Write(ContentEnd, 0, ContentEnd.Length);//写入结尾                



        HttpWebResponse res;
        try
        {
            res = (HttpWebResponse)request.GetResponse();
        }
        catch (WebException ex)
        {
            res = (HttpWebResponse)ex.Response;
        }
        //StreamReader sr = new StreamReader(res.GetResponseStream(), strEncode);
        //strHtml = sr.ReadToEnd();
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();


        //获取返回值
        Stream myResponseStream = response.GetResponseStream();
        StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));

        string retString = myStreamReader.ReadToEnd();
        myRequestStream.Close();
        myStreamReader.Close();
        myResponseStream.Close();
    }


            以下是抓包截图

            ![图片说明](https://img-ask.csdn.net/upload/202001/09/1578548657_696695.png)

            返回错误信息
            {"timestamp":"2020-01-09 13:40:35","status":500,"error":"Internal Server Error","message":"Failed to parse multipart servlet request; nested exception is org.apache.commons.fileupload.FileUploadBase$IOFileUploadException: Processing of multipart/form-data request failed. Stream ended unexpectedly","path":"/lab/calibrator/uploadReport"}

Answer 1

估计你multipart数据编码有问题，直接用 webclient.upload 上传。感觉你直接写二进制了，没有做base64编码