webclient 和httpclient 应用

图片上传与展示

最新推荐文章于 2025-04-08 16:17:35 发布

转载最新推荐文章于 2025-04-08 16:17:35 发布 · 842 阅读

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/shiyh/p/9273619.html

文章标签：

#java #嵌入式 #json

本文介绍了一个基于MVC架构的应用程序中实现文件上传、图片展示及服务器选择的功能。具体包括使用WebClient进行文件上传、从数据库中获取图片服务器信息以及通过HTTP客户端进行数据交互等关键步骤。

//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, 0, buffer.Length);
            stream.Seek(0, 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

转载于:https://www.cnblogs.com/shiyh/p/9273619.html