/// base64上传图片        ///          /// 
     
      成功上传返回上传后的文件名
             [HttpPost]        public async Task
     
       UpLoadImageBase64()        {            HttpContextBase context = (HttpContextBase)Request.Properties["MS_HttpContext"];            string text = context.Request.Form["file"];            Stream stream = new MemoryStream(Convert.FromBase64String(text.Split(',')[1]));            using (HttpClient client = new HttpClient())            {                var request = new HttpRequestMessage(HttpMethod.Post, ConfigurationManager.AppSettings["Imgaes"].ToString() + "/Upload");                var content = new MultipartFormDataContent();                //client.DefaultRequestHeaders.Add("fileext", HttpContext.Request.Headers["fileext"]);                content.Add(new StreamContent(stream), "file", "file.jpg");                request.Content = content;                var response = await client.SendAsync(request);                response.EnsureSuccessStatusCode();                var filenamestr = await response.Content.ReadAsStringAsync();//返回结果            }            return Ok();        }