.NET Core 多文件带参数Post上传

            string url = string.Format("{0}/api/FileUpload/xxx", "http://192.168.1.1:80xx");
            Dictionary<string, object> parameters = new Dictionary<string, object>();
            List<string> files = new List<string>();
            files.Add($"{path}\\{fName}");
            parameters.Add("files", files);
            parameters.Add("ter", ster);
            parameters.Add("img", "");
            
    public const string Token = "U0pfVG9rZW5fMjRiZGViYjNmZmRlNGYxOGI0MTZkNzhkMTFjNDlmZWU="; //测试token  
        public static HttpWebResponse PostFile(string url, IDictionary<string, object> kys = null, string postdata = null)
        {

        //即将上传的文件根路径
            string filepath = Path.Combine(AppContext.BaseDirectory, "Screen");

            Dictionary<string, object> files = new Dictionary<string, object>();
            foreach (var item in kys)
            {
                if (item.Key=="files")
                {
                    List<string> jsonFile =  JsonConvert.DeserializeObject<List<string>>(JsonConvert.SerializeObject(item.Value));
                    foreach (var item2 in jsonFile)
                    {
                        files.Add(Path.GetFileName(item2), item2);
                    }
                }
               
            }

            //上传接口地址
            var webRequest = HttpWebRequest.Create(url);

            webRequest.Method = "POST"; //POST提交方式
            webRequest.Timeout = 60000; //请求超时时间
            webRequest.Headers.Add("token", Token); // ** token 必填

            // 边界符 定义
            var boundary = "------WebKitFormBoundary" + DateTime.Now.Ticks.ToString("x");
            webRequest.ContentType = "multipart/form-data; boundary=" + boundary; //form-data 形式的请求头类型

            //用于打印的可以忽略
            string start = "--" + boundary + "\r\n";
            string end = "--" + boundary + "--\r\n";
            string newline = "\r\n";

            //写入流的固定格式值
            var beginBoundary = Encoding.ASCII.GetBytes("--" + boundary + "\r\n");   // 开始边界符
            var endBoundary = Encoding.ASCII.GetBytes("--" + boundary + "--\r\n");  // 结束结束符
            var newLineBytes = Encoding.UTF8.GetBytes("\r\n");    //换行符 



            //区分上传类型 获得 content 类型
            Func<string, string> getcontent = (s) =>
            {
                var ex = Path.GetExtension(s); //拿到后缀
                return FileContentType.GetMimeType(ex);//FileContentType.GetMimeType(ex); //请求后缀返回对应的 type类型
                                                        //PS 获取Content-Type 的 三种方法传送门：https://blog.csdn.net/a873744779/article/details/100514010
            };

            using (var stream = new MemoryStream())
            {


                // 写入字段参数
                var keyValue = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";
                // 装载form表单字段【非上传文件字段】
                foreach (string key in kys.Keys)
                {
                    //参数字段转字节
                    var keyValueBytes = Encoding.UTF8.GetBytes(string.Format(keyValue, key, kys[key]));
                    stream.Write(beginBoundary, 0, beginBoundary.Length);//写入边界开始
                    stream.Write(keyValueBytes, 0, keyValueBytes.Length);//写入字节
                    stream.Write(newLineBytes, 0, newLineBytes.Length);//写入换行符
                }

                //多文件上传
                foreach (var item in files)
                {

                    var fileData = File.ReadAllBytes(item.Value.ToString()); //读文件流 

                    // 写入文件  name = \"Files\"  这里对应的是接口参数 List<IfromFile> Files
                    var fileHeader = "Content-Disposition: form-data; name=\"Files\"; filename=\"" + item.Key + "\"\r\n"
                    + "Content-Type: " + getcontent(item.Key) + "\r\n\r\n";
                    var fileHeaderBytes = Encoding.UTF8.GetBytes(fileHeader);
                    stream.Write(beginBoundary, 0, beginBoundary.Length);// 写入开始边界
                    stream.Write(fileHeaderBytes, 0, fileHeaderBytes.Length);//写入文件格式对象流
                    stream.Write(fileData, 0, fileData.Length);  // 写入文件流对象
                    stream.Write(newLineBytes, 0, newLineBytes.Length);//写入换行符

                }

                Console.WriteLine(end);//打印结束边界
                // 写入结束边界符
                stream.Write(endBoundary, 0, endBoundary.Length);
                webRequest.ContentLength = stream.Length;//设置请求对象，字节长度总量
                stream.Position = 0;//指定流开始索引
                var tempBuffer = new byte[stream.Length];//定义新字节流对象，用于提交请求结果
                stream.Read(tempBuffer, 0, tempBuffer.Length); //从0开始索引读流到新 tempbuffer 对象

                //请求结果流
                using (Stream requestStream = webRequest.GetRequestStream())
                {
                    requestStream.Write(tempBuffer, 0, tempBuffer.Length);//写入请求流
                    using (var response = webRequest.GetResponse())//请求结果流
                    using (StreamReader httpStreamReader = new StreamReader(response.GetResponseStream(), Encoding.UTF8)) //从结果流对象中读取结果流并设置流格式转换为 uft8 格式
                    {
                        string result = httpStreamReader.ReadToEnd();//返回服务器返回json
                    }
                }

            }
            return null;
        }

方法

 [HttpPost]
        public IActionResult TerScreenshotUpload(List<IFormFile> files, string ter, string img)
        {

}