发布时间：2023-09-09 来源：win7旗舰版 浏览量：
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网络技术是从1990年代中期发展起来的新技术，它把互联网上分散的资源融为有机整体，实现资源的全面共享和有机协作，使人们能够透明地使用资源的整体能力并按需获取信息。资源包括高性能计算机、存储资源、数据资源、信息资源、知识资源、专家资源、大型数据库、网络、传感器等。 当前的互联网只限于信息共享，网络则被认为是互联网发展的第三阶段。 利用HttpRequest利用HttpRequest登录到某个网站，然后获取网站信息的程序示例 问题：有的网站的相关内容必须要在登录后才可以查看，其登录信息保存在session变量之中。这样，使用asphttp等组件就难以正确得到所要的信息。解决：使用asp.net中的httprequest和httpresponse来实现。要点： 1。 通过附加一个cookiecontainer到httprequest对象中，可以得到登录后返回的代表SESSION ID的COOKIE。 见Login方法 2。 将此COOKIE包含在一个cookiecontainer中并附加到另一个HTTPREQUEST请求中，则可以实现SESSION的还原。见getPage方法源程序如下：getHttpInfo.aspx: <%@ Page language="c#" Codebehind="getHttpInfo.aspx.cs" AutoEventWireup="false" Inherits="PdfTest.getHttpInfo" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" > <HTML> <HEAD> <title>WebForm1</title> <meta content="Microsoft Visual Studio 7.0" name="GENERATOR"> <meta content="C#" name="CODE_LANGUAGE"> <meta content="javascript" name="vs_defaultClientscript"> <meta content="http://schemas.microsoft.com/intellisense/ie5"; name="vs_targetSchema"> </HEAD> <body> <form id="Form1" method="post" runat="server"> </form> </body> </HTML> getHttpInfo.aspx.cs: using System; using System.Collections; using System.ComponentModel; using System.Data; //using System.Data.OleDb; using System.Drawing; using System.Web; using System.Web.SessionState; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; using System.Net; using System.IO; using System.Text; using System.Text.RegularExpressions; using Microsoft.Data.Odbc;namespace PdfTest { /// <summary> /// Summary description for WebForm1. /// </summary> public class getHttpInfo : System.Web.UI.Page { protected static string cookieheader; private void Page_Load(object sender, System.EventArgs e) { // Put user code to initialize the page herestring strResult;if (HttpContext.Current.Application["cookieheader"] != null) { cookieheader = (string)HttpContext.Current.Application["cookieheader"]; } else { //Login into the website and keep the cookie for the session in the application variable string strLogin = Login("http://www.thesiteyouwanttovisit/theloginpage.asp";, "Action=&USERID=&Password=") ; } strResult = getPage("http://www.thesiteyouwanttovisit/theloginpage.asp";, "Action=&data=") ; //Write the result to htm file FileStream htmFile = new FileStream("c:\save.htm", FileMode.OpenOrCreate); StreamWriter sw = new StreamWriter(htmFile); sw.Write(strResult); sw.Close(); htmFile.Close();// output the result Response.Write(strResult); } public static string Login(String url, String paramList) { HttpWebResponse res = null; string strResult="";try {HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url); req.Method = "POST"; req.ContentType = "application/x-www-form-urlencoded"; req.AllowAutoRedirect = false; CookieContainer cookieCon = new CookieContainer(); req.CookieContainer = cookieCon;StringBuilder UrlEncoded = new StringBuilder(); Char[] reserved = {?, =, &}; byte[] SomeBytes = null;if (paramList != null) { int i=0, j; while(i<paramList.Length) { j=paramList.IndexOfAny(reserved, i); if (j==-1) { UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, paramList.Length-i))); break; } UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, j-i))); UrlEncoded.Append(paramList.Substring(j,1)); i = j+1; } SomeBytes = Encoding.UTF8.GetBytes(UrlEncoded.ToString()); req.ContentLength = SomeBytes.Length; Stream newStream = req.GetRequestStream(); newStream.Write(SomeBytes, 0, SomeBytes.Length); newStream.Close(); } else { req.ContentLength = 0; } res = (HttpWebResponse)req.GetResponse(); cookieheader = req.CookieContainer.GetCookieHeader(new Uri(url)); HttpContext.Current.Application.Lock(); HttpContext.Current.Application["cookieheader"] = cookieheader; HttpContext.Current.Application.UnLock();Stream ReceiveStream = res.GetResponseStream(); Encoding encode = System.Text.Encoding.GetEncoding("utf-8"); StreamReader sr = new StreamReader( ReceiveStream, encode ); Char[] read = new Char[256]; int count = sr.Read( read, 0, 256 ); while (count > 0) { String str = new String(read, 0, count); strResult += str; count = sr.Read(read, 0, 256); } } catch(Exception e) { strResult = e.ToString(); } finally { if ( res != null ) { res.Close(); } }return strResult; } public static string getPage(String url, String paramList) { HttpWebResponse res = null; string strResult = "";try {HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url); req.Method = "POST"; req.KeepAlive = true; req.ContentType = "application/x-www-form-urlencoded"; CookieContainer cookieCon = new CookieContainer(); req.CookieContainer = cookieCon; req.CookieContainer.SetCookies(new Uri(url),cookieheader); StringBuilder UrlEncoded = new StringBuilder(); Char[] reserved = {?, =, &}; byte[] SomeBytes = null;if (paramList != null) { int i=0, j; while(i<paramList.Length) { j=paramList.IndexOfAny(reserved, i); if (j==-1) { UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, paramList.Length-i))); break; } UrlEncoded.Append(HttpUtility.UrlEncode(paramList.Substring(i, j-i))); UrlEncoded.Append(paramList.Substring(j,1)); i = j+1; } SomeBytes = Encoding.UTF8.GetBytes(UrlEncoded.ToString()); req.ContentLength = SomeBytes.Length; Stream newStream = req.GetRequestStream(); newStream.Write(SomeBytes, 0, SomeBytes.Length); newStream.Close(); } else { req.ContentLength = 0; } res = (HttpWebResponse)req.GetResponse(); Stream ReceiveStream = res.GetResponseStream(); Encoding encode = System.Text.Encoding.GetEncoding("utf-8"); StreamReader sr = new StreamReader( ReceiveStream, encode ); Char[] read = new Char[256]; int count = sr.Read( read, 0, 256 ); while (count > 0) { String str = new String(read, 0, count); strResult += str; count = sr.Read(read, 0, 256); } } catch(Exception e) { strResult = e.ToString(); } finally { if ( res != null ) { res.Close(); } }return strResult; } #region Web Form Designer generated code override protected void OnInit(EventArgs e) { // // CODEGEN: This call is required by the ASP.NET Web Form Designer. // InitializeComponent(); base.OnInit(e); }/// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load);} #endregion} } 网络的神奇作用吸引着越来越多的用户加入其中，正因如此，网络的承受能力也面临着越来越严峻的考验―从硬件上、软件上、所用标准上......，各项技术都需要适时应势，对应发展，这正是网络迅速走向进步的催化剂。 |
利用HttpRequest利用HttpRequest登录到某个网站，然后获取网站信息的程序示例 问
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