Stringuuid = "";
           //建立HttpClient例項
           HttpClient httpClient = new HttpClient();
           //以下程式碼是獲得當前時間至1970年1月1號的毫秒數
           long currentTicks=DateTime.Now.Ticks;
           DateTime dtFrom = new DateTime(1970, 1, 1, 0, 0, 0, 0);
           long currentMillis = (currentTicks - dtFrom.Ticks) / 10000;
           //獲取微信Web的uuid
           HttpResponseMessage response = httpClient.GetAsync("https://login.weixin.qq.com/jslogin?appid=wx782c26e4c19acffb&redirect_uri=https%3A%2F%2Fwx.qq.com%2Fcgi-bin%2Fmmwebwx-bin%2Fwebwxnewloginpage&fun=new&lang=zh_CN&_=";+ currentMillis.ToString()).Result;
           //判斷是否成功
           if (response.IsSuccessStatusCode)
            {
               String result = response.Content.ReadAsStringAsync().Result;
               //通過正則表示式獲取uuid
               String ss="window.QRLogin.code = (\\d+); window.QRLogin.uuid = \"(\\S+?)\";";
               Regex regex =new Regex(ss);
               Match match = regex.Match(result);
                uuid=match.Groups[2].Value;
               //獲取uuid後，通過uuid獲得登入二維碼，這裡返回的png位元組流
                response=httpClient.GetAsync("https://login.weixin.qq.com/qrcode/";+ uuid).Result;
               byte[] bytes = response.Content.ReadAsByteArrayAsync().Result;//  .ReadAsStreamAsync().Result;
               //在本地建立png檔案，把返回的二維碼圖片儲存在png檔案中
               FileStream pngFile = new FileStream("d:\\anxiuyun\\login\\kk.png",FileMode.Create);
                pngFile.Write(bytes,0,bytes.Length);
                pngFile.Flush();
                pngFile.Close();
            }