C# HTTP或HTTPS Get请求 和 Post 请求

private string GetUrl(string url)
{
    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
    if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
    {
        ServicePointManager.ServerCertificateValidationCallback = (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) => true;
        request.ProtocolVersion = HttpVersion.Version11;
        // 这里设置了协议类型。
        ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;// SecurityProtocolType.Tls1.2; 
        request.KeepAlive = false;
        ServicePointManager.CheckCertificateRevocationList = true;
        ServicePointManager.DefaultConnectionLimit = 100;
        ServicePointManager.Expect100Continue = false;
    }
    request.Method = "GET";    //使用get方式发送数据
    request.ContentType = "application/x-www-form-urlencoded";
    request.Referer = null;
    request.AllowAutoRedirect = true;
    request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
    request.Accept = "*/*";

    //获取网页响应结果
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    Stream stream = response.GetResponseStream();
    //client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
    string result = string.Empty;
    using (StreamReader sr = new StreamReader(stream))
    {
        result = sr.ReadToEnd();
    }

    return result;
}

private static string PostUrl(string url, string postData)
{
    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
    if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
    {
        ServicePointManager.ServerCertificateValidationCallback = (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) => true;
        request.ProtocolVersion = HttpVersion.Version11;
　　　　　　　　　// 这里设置了协议类型。
        ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;// SecurityProtocolType.Tls1.2; 
        request.KeepAlive = false;
        ServicePointManager.CheckCertificateRevocationList = true;
        ServicePointManager.DefaultConnectionLimit = 100;
        ServicePointManager.Expect100Continue = false;
    }
    request.Method = "POST";    //使用get方式发送数据
    request.ContentType = "application/x-www-form-urlencoded";
    request.Referer = null;
    request.AllowAutoRedirect = true;
    request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
    request.Accept = "*/*";

    byte[] data = Encoding.UTF8.GetBytes(postData);
    Stream newStream = request.GetRequestStream();
    newStream.Write(data, 0, data.Length);
    newStream.Close();

    //获取网页响应结果
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    Stream stream = response.GetResponseStream();
    //client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
    string result = string.Empty;
    using (StreamReader sr = new StreamReader(stream))
    {
        result = sr.ReadToEnd();
    }

    return result;
}