webclient 和httpclient 应用

//webclient应用
 MyImageServerEntities db = new MyImageServerEntities();
        public ActionResult Index()
        {
            return View();
        }
        public ActionResult FileUpload()
        {
            HttpPostedFileBase file = Request.Files["fileUp"];
            string fileName = Path.GetFileName(file.FileName);
            string fileExt = Path.GetExtension(fileName);
            if (fileExt == ".jpg")
            {
              var list=db.ImageServerInfo.Where<ImageServerInfo>(u => u.FlgUsable == true).ToList();//找出可用的图片服务器.
              int count = list.Count();
              Random random = new Random();
              int r = random.Next();
              int i = r % count;
              string serverUrl = list[i].ServerUrl;
              int serverId = list[i].ServerId;
              string url = "http://"+serverUrl+"/FileUp.ashx?serverId="+serverId+"&fileExt="+fileExt;
              WebClient webClient =new WebClient();
              webClient.UploadData(url, StreamToBytes(file.InputStream));

            }
            return Content("ok");

        }
        public ActionResult ShowImage()
        {
          var list=  db.ImageServerInfo.Where<ImageServerInfo>(c=>c.FlgUsable==true).ToList();
          ViewData["imageServerList"] = list;
          return View();
        }
        private byte[] StreamToBytes(Stream stream)
        {
            byte[]buffer=new byte[stream.Length];
            stream.Read(buffer, , buffer.Length);
            stream.Seek(, SeekOrigin.Begin);
            return buffer;
        }

           context.Response.ContentType = "text/plain";
            int serverId = int.Parse(context.Request["serverId"]);
            string fileExt = context.Request["fileExt"];
            string dir = "/ImagePath/" + DateTime.Now.Year + "/" + DateTime.Now.Month + "/" + DateTime.Now.Day + "/";
            Directory.CreateDirectory(Path.GetDirectoryName(context.Request.MapPath(dir)));
            string newfileName = Guid.NewGuid().ToString();
            string fullDir = dir + newfileName + fileExt;
            using (FileStream fileStream = File.Open(context.Request.MapPath(fullDir), FileMode.OpenOrCreate))
            {
                context.Request.InputStream.CopyTo(fileStream);
                MyImageServerEntities db = new MyImageServerEntities();
                ImageInfo imageInfo = new ImageInfo();
                imageInfo.ImageName = fullDir;
                imageInfo.ImageServerId = serverId;
                db.ImageInfo.Add(imageInfo);
                db.SaveChanges();

            }

　　

//httpclient 应用

创建并初始化对象：
    client.BaseAddress = new Uri(url);
    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

读集合：
    HttpResponseMessage response = client.GetAsync(url).Result;
     var userList = response.Content.ReadAsAsync<IEnumerable<数据类型>>().Result;

根据编号读对象
    HttpResponseMessage response1 = client.GetAsync(url).Result;
    var userInfo = response1.Content.ReadAsAsync<数据类型>().Result;

增加：
    HttpResponseMessage response = client.PostAsJsonAsync("api/userinfo", userInfo).Result;
    使用response.IsSuccessStatusCode判断是否成功
    使用response.Content.ToString()获取返回值

修改：
     HttpResponseMessage response = client.PutAsJsonAsync("api/userinfo/"+userInfo.UserId, userInfo).Result;
    使用response.IsSuccessStatusCode判断是否成功
    使用response.Content.ToString()获取返回值

删除：
    HttpResponseMessage response = client.DeleteAsync("api/userinfo/" + uid).Result;
    使用response.IsSuccessStatusCode判断是否成功
    使用response.Content.ToString()获取返回值