我們檢測到您的瀏覽器不兼容傳輸層安全協議 (TLS) 1.1 或更高版本，此協議在 Internet 上用於確保您通信的安全性。

早上使用.Net WebClient類采集亞馬遜數據，返回http 400 Bad Request錯誤，內容里面有“我們檢測到您的瀏覽器不兼容傳輸層安全協議 (TLS) 1.1 或更高版本，此協議在 Internet 上用於確保您通信的安全性。”

所以就想着可能是WebClient使用TLS版本過低，查了下資料，全局加上這段代碼。

            ServicePointManager.ServerCertificateValidationCallback += ValidateRemoteCertificate;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

        /// <summary>
        /// Certificate validation callback.
        /// </summary>
        private static bool ValidateRemoteCertificate(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors error)
        {
            // If the certificate is a valid, signed certificate, return true.
            if (error == System.Net.Security.SslPolicyErrors.None)
            {
                return true;
            }

            Console.WriteLine("X509Certificate [{0}] Policy Error: '{1}'",
                cert.Subject,
                error.ToString());

            return false;
        }

 

參考鏈接：https://stackoverflow.com/questions/20064505/requesting-html-over-https-with-c-sharp-webclient