c# HttpWebRequest与HttpWebResponse 绝技

1.第一招，根据URL地址获取网页信息

   先来看一下代码

get方法

 public static string GetUrltoHtml(string Url,string type)
        {
            try
            {
                System.Net.WebRequest wReq = System.Net.WebRequest.Create(Url);
                // Get the response instance.
                System.Net.WebResponse wResp = wReq.GetResponse();
                System.IO.Stream respStream = wResp.GetResponseStream();
                // Dim reader As StreamReader = New StreamReader(respStream)
                using (System.IO.StreamReader reader = new System.IO.StreamReader(respStream, Encoding.GetEncoding(type)))
                {
                    return reader.ReadToEnd();
                }
            }
            catch (System.Exception ex)
            {
                //errorMsg = ex.Message;
            }
            return "";
        }

post方法

  ///<summary>
        ///采用https协议访问网络
        ///</summary>
        ///<param name="URL">url地址</param>
        ///<param name="strPostdata">发送的数据</param>
        ///<returns></returns>
        public string OpenReadWithHttps(string URL, string strPostdata, string strEncoding)
        {
            Encoding encoding = Encoding.Default;
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
            request.Method = "post";
            request.Accept = "text/html, application/xhtml+xml, */*";
            request.ContentType = "application/x-www-form-urlencoded";
            byte[] buffer = encoding.GetBytes(strPostdata);
            request.ContentLength = buffer.Length;
            request.GetRequestStream().Write(buffer, 0, buffer.Length);
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            using( StreamReader reader = new StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding(strEncoding)))

              {
                   return reader.ReadToEnd();

              }
        }

 

这招是入门第一式， 特点：

   1.最简单最直观的一种，入门课程。

   2.适应于明文，无需登录，无需任何验证就可以进入的页面。

   3.获取的数据类型为HTML文档。

   4.请求方法为Get/Post

 

2.第二招，根据URL地址获取需要验证证书才能访问的网页信息

   先来看一下代码

 get方法

  //回调验证证书问题
        public bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {   // 总是接受    
            return true;
        }

        /// <summary>
        /// 传入URL返回网页的html代码
        /// </summary>
        /// <param name="Url">URL</param>
        /// <returns></returns>
        public string GetUrltoHtml(string Url)
        {
            StringBuilder content = new StringBuilder();

            try
            {
                //这一句一定要写在创建连接的前面。使用回调的方法进行证书验证。
                ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);

                // 与指定URL创建HTTP请求
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);

                //创建证书文件
                X509Certificate objx509 = new X509Certificate(Application.StartupPath + "\\123.cer");

                //添加到请求里
                request.ClientCertificates.Add(objx509);

                // 获取对应HTTP请求的响应
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                // 获取响应流
                Stream responseStream = response.GetResponseStream();
                // 对接响应流(以"GBK"字符集)
                StreamReader sReader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
                // 开始读取数据
                Char[] sReaderBuffer = new Char[256];
                int count = sReader.Read(sReaderBuffer, 0, 256);
                while (count > 0)
                {
                    String tempStr = new String(sReaderBuffer, 0, count);
                    content.Append(tempStr);
                    count = sReader.Read(sReaderBuffer, 0, 256);
                }
                // 读取结束
                sReader.Close();
            }
            catch (Exception)
            {
                content = new StringBuilder("Runtime Error");
            }

            return content.ToString();

        }