如果你想做一些，抓取，或者是自动获取的功能，那么就跟我一起来学习一下Http请求吧。
本文章会对Http请求时的Get和Post方式进行详细的说明，
在请求时的参数怎么发送，怎么带Cookie，怎么设置证书，怎么解决 编码等问题，进行一步一步的解决。
* 如果要使用中间的方法的话，可以访问我的帮助类完全免费开源：
这个类是专门为HTTP的GET和POST请求写的，解决了编码，证书，自动带Cookie等问题。
C# HttpHelper,帮助类,真正的Httprequest请求时无视编码，无视证书，无视Cookie,网页抓取
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>url地址</param> ///<param>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>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(); }
post方法