ASP.NET WebApi 实现多附件上传

前几天调查 ASP.NET WebApi 实现 multipart/form-data 文件上传功能时，遇到一个问题正好记录下来。

multipart/form-data 经常用于多附件上传，其中数据是以 boundary 进行分割，形如：

紧接着 boundary 的是该部分数据的描述。形如：

服务端代码：

// POST api/values
        public HttpResponseMessage Post()
        {
            var content = Request.Content;
            var uploadDir = HttpContext.Current.Server.MapPath("~/Upload");
            var newFileName = "";

            
            var sp = new MultipartMemoryStreamProvider();
            Task.Run(async () => await Request.Content.ReadAsMultipartAsync(sp)).Wait();

            foreach (var item in sp.Contents)
            {
                if (item.Headers.ContentDisposition.FileName != null)
                {
                    var filename = item.Headers.ContentDisposition.FileName.Replace("\"", "");
                    newFileName = uploadDir + "\\" + filename;
                    var ms = item.ReadAsStreamAsync().Result;
                    using (var br = new BinaryReader(ms))
                    {
                        var data = br.ReadBytes((int)ms.Length);
                        File.WriteAllBytes(newFileName, data);
                    }
                }
            }
            
            var result = new Dictionary();
            result.Add("result", newFileName);
            var resp = Request.CreateResponse(HttpStatusCode.OK, result);
            resp.Content.Headers.ContentType = new MediaTypeHeaderValue("text/plain");
            return resp;
        }

细心的你会注意到，这句代码：

Task.Run(async () => await Request.Content.ReadAsMultipartAsync(sp)).Wait();

是不是有冗余的气味？