public static async Task <string> GetWebContent(string url)
        {
            using (var myHttpClientHandler = new MyHttpClientHandler(cookieContainer))
                using (var httpClient = new HttpClient(myHttpClientHandler))
                {
                    Console.WriteLine($"Starting connect {url}");
                    httpClient.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml+json");
                    httpClient.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36");
                    //httpClient.DefaultRequestHeaders.Add("Host", "facebook.com");
                    //httpClient.DefaultRequestHeaders.Add("Connection", "keep-alive");
                    HttpResponseMessage response = await httpClient.GetAsync(url);

                    response.EnsureSuccessStatusCode();
                    byte[] bytes = await response.Content.ReadAsByteArrayAsync();

                    //Encoding encoding = Encoding.GetEncoding("windows-1251");
                    Encoding encoding = Encoding.GetEncoding("utf-8");
                    string   html     = encoding.GetString(bytes, 0, bytes.Length);
                    return(html);
                    //HttpResponseMessage response = await httpClient.GetAsync(url);
                    //response.EnsureSuccessStatusCode();
                    //string htmltext = await response.Content.ReadAsStringAsync();
                    //return htmltext;
                }
        }
        public static async Task <string> GetWebContent(string url)
        {
            using (var myHttpClientHandler = new MyHttpClientHandler(cookieContainer))
                using (var httpClient = new HttpClient(myHttpClientHandler)) {
                    Console.WriteLine($"Starting connect {url}");
                    httpClient.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml+json");
                    httpClient.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36");
                    HttpResponseMessage response = await httpClient.GetAsync(url);

                    response.EnsureSuccessStatusCode();
                    string htmltext = await response.Content.ReadAsStringAsync();

                    return(htmltext);
                }
        }
        public static async Task <string> GetWebContent(string url, string cookieStr)
        {
            CookieContainer cookieContainer = new CookieContainer();  // Sử dụng CookieContainer riêng, để lưu lại Cookie - hoặc thêm cookie
            var             arrCookie       = cookieStr.Split(';');

            foreach (var cookie in arrCookie)
            {
                var arr = cookie.Split('=');
                if (arr.Length > 1)
                {
                    cookieContainer.Add(new Uri(url), new Cookie(arr[0].Trim(), arr[1].Trim()));
                }
            }

            using (var myHttpClientHandler = new MyHttpClientHandler(cookieContainer))
                using (var httpClient = new HttpClient(myHttpClientHandler))
                {
                    Console.WriteLine($"Starting connect {url}");
                    httpClient.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml+json");
                    httpClient.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36");
                    //httpClient.DefaultRequestHeaders.Add("Host", "facebook.com");
                    //httpClient.DefaultRequestHeaders.Add("Connection", "keep-alive");
                    HttpResponseMessage response = await httpClient.GetAsync(url);

                    response.EnsureSuccessStatusCode();
                    byte[] bytes = await response.Content.ReadAsByteArrayAsync();

                    //Encoding encoding = Encoding.GetEncoding("windows-1251");
                    Encoding encoding = Encoding.GetEncoding("utf-8");
                    string   html     = encoding.GetString(bytes, 0, bytes.Length);
                    return(html);
                    //HttpResponseMessage response = await httpClient.GetAsync(url);
                    //response.EnsureSuccessStatusCode();
                    //string htmltext = await response.Content.ReadAsStringAsync();
                    //return htmltext;
                }
        }