C# can'；无法使用https获取web响应

我使用此代码获取web内容，但在

WebResponse myResponse=myRequest.GetResponse（）处获取异常

我知道它需要SSL/TLS证书，但我想知道为什么我仍然会出错

试试这个

    static void Main(string[] args)
    {
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
        var client = new HttpClient();
        var result = client.GetAsync("https://www.ecfr.gov").Result;
        var str = result.Content.ReadAsStringAsync().Result;
    }

任何时候你“得到异常”你都需要告诉我们异常是什么。
    static void Main(string[] args)
    {
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
        var client = new HttpClient();
        var result = client.GetAsync("https://www.ecfr.gov").Result;
        var str = result.Content.ReadAsStringAsync().Result;
    }