HttpWebRequest和HttpWebResponse类是用于发送和接收HTTP数据的最好选择。它们支持一系列有用的属性。
模拟艺龙旅游网登录
想模拟登录，首先整理一下流程
1.通过360浏览器(IE,火狐等等)F12开发人员工具抓到相关数据
2.获取验证码（拿到cookie），登录时也需要使用
3.登录
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F12调出开发人员工具，输入用户名，密码登录，看我们抓到了什么信息。 （此处为360浏览器）
Request URL:这个就是登录请求的url
https://secure.elong.com/passport/ajax/elongLogin
方式POST
Form Data:这个是我们要POST传输的数据：
userName=xzdylyh&passwd=12313&validateCode=验证码&rememberMe=false （注意此处可能每个人略有不同）
其它一些重要信息在Request Headers中
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我使用C# 设计的winform界面
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Web;using System.Net;using System.IO;using System.Data;namespace HTTPHELPER{ ???public ?class ELOGN_LOGIN ???{ ??????public static CookieContainer container = null; //存储验证码cookie ???????#region 登录 ???????public string ?requestM(string uName,string passwd,string vaildate) ???????{ ???????????HttpWebRequest request = null; ???????????HttpWebResponse response = null; ???????????try ???????????{ ???????????????request = (HttpWebRequest)HttpWebRequest.Create("https://secure.elong.com/passport/ajax/elongLogin"); ???????????????request.Method = "Post"; ???????????????request.ContentType = "application/x-www-form-urlencoded; charset=UTF-8"; ???????????????request.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36"; ???????????????request.AllowAutoRedirect = true; ???????????????request.CookieContainer = container;//获取验证码时候获取到的cookie会附加在这个容器里面 ???????????????request.KeepAlive = true;//建立持久性连接 ???????????????//整数据 ???????????????string postData = string.Format("userName={0}&passwd={1}&validateCode={2}&rememberMe=true", uName, passwd, vaildate); ???????????????ASCIIEncoding encoding = new ASCIIEncoding(); ???????????????byte[] bytepostData = encoding.GetBytes(postData); ???????????????request.ContentLength = bytepostData.Length; ???????????????//发送数据 ?using结束代码段释放 ???????????????using (Stream requestStm = request.GetRequestStream()) ???????????????{ ???????????????????requestStm.Write(bytepostData, 0, bytepostData.Length); ???????????????} ???????????????//响应 ???????????????response = (HttpWebResponse)request.GetResponse(); ???????????????string text = string.Empty; ???????????????using (Stream responseStm = response.GetResponseStream()) ???????????????{ ???????????????????StreamReader redStm = new StreamReader(responseStm, Encoding.UTF8); ???????????????????text = redStm.ReadToEnd(); ???????????????} ??????????????return text; ???????????} ???????????catch (Exception ex) ???????????{ ???????????????var msg = ex.Message; ???????????????return msg; ???????????} ???????} ???????#endregion ????????#region 获取验证码 ???????public Stream getCodeStream(string codeUrl) ???????{ ???????????//验证码请求 ??????????HttpWebRequest request = (HttpWebRequest)WebRequest.Create(codeUrl); ???????????request.Method = "GET"; ???????????request.ContentType = "application/x-www-form-urlencoded"; ???????????request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:5.0.1) Gecko/20100101 Firefox/5.0.1"; ???????????request.Accept = "image/webp,*/*;q=0.8"; ???????????request.CookieContainer = new CookieContainer();//!Very Important.!!! ???????????container = request.CookieContainer; ???????????var c = request.CookieContainer.GetCookies(request.RequestUri); ???????????HttpWebResponse ?response = (HttpWebResponse)request.GetResponse(); ???????????response.Cookies = container.GetCookies(request.RequestUri); ???????????????????Stream stream = response.GetResponseStream(); ?????????return stream; ???????} ???} ???????#endregion}using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;using System.IO;using HTTPHELPER;namespace WindowsFormsApplication8{ ???public partial class ELONG_LOGIN_FORM : Form ???{ ???????public ELONG_LOGIN_FORM() ???????{ ???????????InitializeComponent(); ???????} ???????private void button1_Click(object sender, EventArgs e) ???????{ ???????????????????????ELOGN_LOGIN elongLogin = new ELOGN_LOGIN(); ???????????????????????var rmsg = elongLogin.requestM(txtuserName.Text,txtPassword.Text,txtVaildata.Text); ???????????MessageBox.Show(rmsg); ???????} ???????private void ELONG_LOGIN_FORM_Load(object sender, EventArgs e) ???????{ ???????????ReflshPicImage();//更新验证码 ???????} ???????//更新验证码 ???????public void ReflshPicImage() ???????{ ???????????string codeUrl = "https://secure.elong.com/passport/getValidateCode"; ???????????ELOGN_LOGIN agent = new ELOGN_LOGIN(); ???????????Stream stmImage = agent.getCodeStream(codeUrl); ???????????picValidate.Image = Image.FromStream(stmImage); ???????} ???????private void btnReValidate_Click(object sender, EventArgs e) ???????{ ???????????ReflshPicImage();//更新验证码 ???????} ???????private void picValidate_Click(object sender, EventArgs e) ???????{ ???????????ReflshPicImage();//更新验证码 ???????} ???}}最后执行效果，登录的session已经成功返回。
原文链接：https://www.cnblogs.com/yhleng/p/6728864.html
ASP.NET HttpWebRequest和HttpWebResponse
原文地址：https://www.cnblogs.com/Liyuting/p/8144935.html