C# WinForm调用net core实现文件上传接口

private void button3_click(object sender, eventargs e)
        {
            var uriaddress = "https://localhost:44381/file/api/voiceasrt/wavconvertfile";
            //var uploadfilepath = "g:\\baidunetdiskdownload\\林俊杰 - 可惜没如果.wav";
            var uploadfilepath = "h:\\安装步骤.txt";
            //uploadfile(uriaddress, uploadfilepath);
            updatefile(uriaddress, uploadfilepath);
        }
 
        //测试ok
        /// <summary>
        /// 单个文件上传至服务器 413是文件太大的错，默认应该是大于4m就会报错，要修改相关配置
        /// public async task<ajaxresult> wavconvertfile([fromform] iformfilecollection files)
        /// 文件上传接口调用测试成功
        /// </summary>
        /// <param name="uriaddress">接收文件资源的uri, 例如: http://xxxx/upload.aspx</param>
        /// <param name="filepath">要发送的资源文件, 例如: @"d:\workspace\webservice 相关.doc</param>
        /// <returns>返回文件保存的相对路径, 例如: "upload/xxxxx.jpg" 或者出错返回 ""</returns>
        private string uploadfile(string uriaddress, string filepath)
        {
            //利用 webclient
            system.net.webclient webclient = new system.net.webclient();
            webclient.credentials = system.net.credentialcache.defaultcredentials;
            try
            {
                byte[] responsearray = webclient.uploadfile(uriaddress, "post", filepath);
                string savepath = system.text.encoding.ascii.getstring(responsearray);
                return savepath;
            }
            catch (exception ex)
            {
                return "";
            }
        }
 
        /// <summary>
        /// 测试ok 
        /// public async task<ajaxresult> wavconvertfile([fromform] iformfilecollection files)
        /// 文件上传接口调用测试成功
        /// </summary>
        /// <param name="url"></param>
        /// <param name="filepath"></param>
        public void updatefile(string url, string filepath)
        {
            try
            {
                string filename_key_ = "kekename\\" + path.getfilename(filepath);
                string access_token = "fz434507768345eb7a8e97897";
                byte[] filecontentbyte = new byte[1024]; // 文件内容二进制
                #region 将文件转成二进制
                filestream fs = new filestream(filepath, filemode.open, fileaccess.read);
                filecontentbyte = new byte[fs.length]; // 二进制文件
                fs.read(filecontentbyte, 0, convert.toint32(fs.length));
                fs.close();
                #endregion
 
                #region 定义请求体中的内容 并转成二进制  *********************************************************      重点 ：拼接参数 *******************************************************
                string boundary = "ceshi";
                string enter = "\r\n";
                //string modelidstr = "--" + boundary + enter
                //        + "content-disposition: form-data; name=\"modelid\"" + enter + enter
                //        + modelid + enter;
 
                string filecontentstr = "--" + boundary + enter
                        + "content-type:application/octet-stream" + enter
                        + "content-disposition: form-data; name=\"file\"; filename=\"" + filepath + "\"" + enter + enter;
 
                string updatetimestr = enter + "--" + boundary + enter
                        + "content-disposition: form-data; name=\"key\"" + enter + enter
                        + filename_key_;
 
                string encryptstr = enter + "--" + boundary + enter
                        + "content-disposition: form-data; name=\"access_token\"" + enter + enter
                        + access_token + enter + "--" + boundary + "--";
 
                // var modelidstrbyte = encoding.utf8.getbytes(modelidstr);//modelid所有字符串二进制
                var filecontentstrbyte = encoding.utf8.getbytes(filecontentstr);//filecontent一些名称等信息的二进制（不包含文件本身）
                var updatetimestrbyte = encoding.utf8.getbytes(updatetimestr);//updatetime所有字符串二进制
                var encryptstrbyte = encoding.utf8.getbytes(encryptstr);//encrypt所有字符串二进制
                #endregion *********************************************************      重点 ：拼接参数 *******************************************************
 
 
                httpwebrequest request = (httpwebrequest)webrequest.create(url);
                request.method = "post";
                request.contenttype = "multipart/form-data;boundary=" + boundary;
 
                stream myrequeststream = request.getrequeststream();//定义请求流
 
                #region 将各个二进制 安顺序写入请求流 modelidstr -> (filecontentstr + filecontent) -> uodatetimestr -> encryptstr
                // myrequeststream.write(modelidstrbyte, 0, modelidstrbyte.length);
                myrequeststream.write(filecontentstrbyte, 0, filecontentstrbyte.length);
                myrequeststream.write(filecontentbyte, 0, filecontentbyte.length);
                myrequeststream.write(updatetimestrbyte, 0, updatetimestrbyte.length);
                myrequeststream.write(encryptstrbyte, 0, encryptstrbyte.length);
                #endregion
 
                httpwebresponse response = (httpwebresponse)request.getresponse();//发送
                stream myresponsestream = response.getresponsestream();//获取返回值
                streamreader mystreamreader = new streamreader(myresponsestream, encoding.getencoding("utf-8"));
 
                string retstring = mystreamreader.readtoend();
                mystreamreader.close();
                myresponsestream.close();
 
                jobject jo = (jobject)jsonconvert.deserializeobject(retstring);
                string code = jo["code"].tostring();
                string desc = jo["desc"].tostring();
                string data = jo["data"].tostring();
                jobject datajson = (jobject)jsonconvert.deserializeobject(data);
                string file_url_ = datajson["file_url"].tostring();
                //if (code == "0")
                //{
                //    updateimgserialinfo("5", file_url_);
                //}
                //else
                //{
                //    salmessage.error("上传图片失败,接口返回：" + desc);
                //}
 
            }
            catch (exception ex)
            {
                //salmessage.error("上传图片出错：" + ex);
            }
        }

/// <summary>
        /// wav 文件转写
        /// </summary>
        /// <param name="files"></param>
        /// <returns></returns>
        [httppost]
        public async task<ajaxresult> wavconvertfile([fromform] iformfilecollection files)
        {
            try
            {
                if (files != null && files.count > 0)
                {
                    string filename = files[0].name;
                    if (path.getextension(filename).equals("wav"))
                    {
                        int maxsize = int.parse(ld.code.configurationmanager.upfileoptions["maxsize"]);
                        if (files[0].length <= maxsize)//检查文件大小
                        {
                            //&& path.getextension(wavfile.name).equals("wav")
                            if (_speechrecognizer != null)
                            {
                                // 从缓存中读取wave数据，并送去语音识别
                                //stream wavememstream = wavfile;
 
                                string uploadfilepath = ld.code.configurationmanager.upfileoptions["uploadfilepath"];
                                string cdipath = directory.getcurrentdirectory();
                                string upfiledirepath = cdipath + uploadfilepath + "wavfiles\\" + filename;
                                using (filestream filestream = new system.io.filestream(upfiledirepath, system.io.filemode.openorcreate, system.io.fileaccess.readwrite, system.io.fileshare.readwrite, maxsize))
                                {
                                    await files[0].copytoasync(filestream);
                                    wavedata wav = sdk.readwavedatas(filestream);
                                    asrtapiresponse rsp = await _speechrecognizer.recogniteasync(wav.bytewavs, wav.samplerate, wav.channels, wav.bytewidth);
                                    asrtresult result = new asrtresult((string)rsp.result, true, rsp.statuscode, rsp.statusmessage);
                                    logfactory.getlogger("wavconvert").info("wavconvert 接口处理请求:" + filename + "文件的转写结果：" + result.text);
                                    return success(result.text, "转写成功");
                                }
                            }
                            else
                            {
                                return error("asrt 服务器api初始化失败");
                            }
                        }
                        else
                        {
                            return error("文件太大了");
                        }
                    }
                    else
                    {
                        return error("语音文件类型错误");
                    }
                }
                else
                {
                    return error("语音文件类型错误");
                }
            }
            catch (system.exception ex)
            {
                logfactory.getlogger("lawcaseevidenceuploadfileasync").info("报错" + ex.message);
                return error("转写报错:" + ex.message);
            }
        }

   /**/ /// <summary>
        /// webclient上传文件至服务器
        /// </summary>
        /// <param name="localfilepath">文件名，全路径格式</param>
        /// <param name="serverfolder">服务器文件夹路径</param>
        /// <param name="rename">是否需要修改文件名，这里默认是日期格式</param>
        /// <returns></returns>
          public   static   bool  uploadfile( string  localfilepath,  string  serverfolder, bool  rename)
        ... {
            string filenameext, newfilename, uristring;
            if (rename)
            ...{
                filenameext = localfilepath.substring(localfilepath.lastindexof(".") + 1);
                newfilename = datetime.now.tostring("yymmddhhmmss") + filenameext;
            }
            else
            ...{
                newfilename = localfilepath.substring(localfilepath.lastindexof("")+1);
            } 
            if (!serverfolder.endswith("/") && !serverfolder.endswith(""))
            ...{
                serverfolder = serverfolder + "/";
            }

            uristring = serverfolder + newfilename;   //服务器保存路径
            /**//// 创建webclient实例
            webclient mywebclient = new webclient();
            mywebclient.credentials = credentialcache.defaultcredentials;

            // 要上传的文件
            filestream fs = new filestream(newfilename, filemode.open, fileaccess.read);
            binaryreader r = new binaryreader(fs);
            try
            ...{
                //使用uploadfile方法可以用下面的格式
                //mywebclient.uploadfile(uristring,"put",localfilepath);
                byte[] postarray = r.readbytes((int)fs.length);
                stream poststream = mywebclient.openwrite(uristring, "put");
                if (poststream.canwrite)
                ...{
                    poststream.write(postarray, 0, postarray.length);
                }
                else
                ...{
                    messagebox.show("文件目前不可写！");
                }
                poststream.close();
            }
            catch
            ...{
                //messagebox.show("文件上传失败，请稍候重试~");
                return false;
            }

            return true;
        }
      

         /**/ /// <summary>
        /// 下载服务器文件至客户端
        /// </summary>
        /// <param name="uri">被下载的文件地址</param>
        /// <param name="savepath">另存放的目录</param>
          public   static   bool  download( string  uri,  string  savepath)
        ... {
            string filename;  //被下载的文件名
            if (uri.indexof("") > -1)
            ...{
                filename = uri.substring(uri.lastindexof("") + 1);
            }
            else
            ...{
                filename = uri.substring(uri.lastindexof("/") + 1);  
            }


            if (!savepath.endswith("/") && !savepath.endswith(""))
            ...{
                savepath = savepath + "/";
            }

            savepath += filename;   //另存为的绝对路径＋文件名

            webclient client = new webclient();
            try
            ...{
                client.downloadfile(uri, savepath);
            }
            catch
            ...{
                return false;
            }

            return true;
        }