HttpClient 同时上传多个文件及参数, 同时利用 Web Api 接收

            using (System.Net.Http.HttpClient client = new System.Net.Http.HttpClient()) {

                client.BaseAddress = new Uri("http://192.168.1.3:42561");
                string api = "api/upload/uploadpost";

                MultipartFormDataContent content = new MultipartFormDataContent();
                string path1 = @"H:图片1.jpg";
                string path2 = @"H:图片2.jpg";
                FileStream fs1 = new FileStream(path1, FileMode.Open, FileAccess.Read);
                FileStream fs2 = new FileStream(path2, FileMode.Open, FileAccess.Read);
                content.Add(new StreamContent(fs1), "myFile1", Guid.NewGuid() + ".jpg");
                content.Add(new StreamContent(fs2), "myFile2", Guid.NewGuid() + ".jpg"); 

                //还可以添加键值对参数,web api 可以通过 request.Form["id"] 接收
                content.Add(new StringContent("1"), "id");
                content.Add(new StringContent("wjire"), "name");
                content.Add(new StringContent("33"), "age");

                var result = client.PostAsync(api, content).Result;
                var str = result.Content.ReadAsStringAsync().Result;
                fs1.Dispose();
                fs2.Dispose();
                Console.WriteLine(str);
            }

后台接收:

        public async Task<HttpResponseMessage> UploadPost() {
            var request = HttpContext.Current.Request;
            var id = request.Form["id"];
            var name = request.Form["name"];
            var age = request.Form["age"];
            var files = HttpContext.Current.Request.Files;
            var path = HttpContext.Current.Server.MapPath("/img/");
            if (files.Count > 0) {
                foreach (string file in files) {
                    var img = files[file];
                    if (img?.ContentLength > 0) {
                        var fileName = img.FileName;
                        await Task.Run(() => img.SaveAs(path + fileName));
                    }
                }
                return new HttpResponseMessage(HttpStatusCode.OK)
                {
                     Content = new StringContent("成功@!!!!!")
                };
            } else {
                var stream = request.InputStream;
                if (stream.Length > 0) {
                    var bytes = new byte[stream.Length];
                    stream.Read(bytes, 0, bytes.Length);
                }
            }
            return Request.CreateErrorResponse(HttpStatusCode.BadRequest, "没有文件");
        }