Asp.Net采集网页方法大全(5种)
/// <summary>方法一:比较推荐 /// 用HttpWebRequest取得网页源码 /// 对于带BOM的网页很有效,不管是什么编码都能正确识别 /// </summary> /// <param name="url">网页地址" </param>
/// <returns>返回网页源文件</returns> public static string GetHtmlSource2(string url,Encoding code) { //处理内容 string html = ""; HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.Accept = "*/*"; //接受任意文件 request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.1.4322)"; // 模拟使用IE在浏览 request.AllowAutoRedirect = true;//是否允许302 //request.CookieContainer = new CookieContainer();//cookie容器, request.Referer = url; //当前页面的引用 HttpWebResponse response = (HttpWebResponse)request.GetResponse(); Stream stream = response.GetResponseStream(); StreamReader reader = new StreamReader(stream, code); html = reader.ReadToEnd(); stream.Close(); return html; } //方法二: public static string GetHttpData2(string Url) { string sException = null; string sRslt = null; WebResponse oWebRps = null; WebRequest oWebRqst = WebRequest.Create(Url); oWebRqst.Timeout = 50000; try { oWebRps = oWebRqst.GetResponse(); } catch (WebException e) { sException = e.Message.ToString(); } catch (Exception e) { sException = e.ToString(); } finally { if (oWebRps != null) { StreamReader oStreamRd = new StreamReader(oWebRps.GetResponseStream(), Encoding.GetEncoding("utf-8")); sRslt = oStreamRd.ReadToEnd(); oStreamRd.Close(); oWebRps.Close(); } } return sRslt; } /// <summary>方法三: /// /// </summary> /// <param name="url">/要访问的网站地址</param> /// <param name="charSets">目标网页的编码,如果传入的是null或者"",那就自动分析网页的编码</param> /// <returns></returns> public static string getHtml(string url, params string[] charSets) { try { string charSet = null; if (charSets.Length == 1) { charSet = charSets[0]; } WebClient myWebClient = new WebClient(); //创建WebClient实例myWebClient // 需要注意的: //有的网页可能下不下来,有种种原因比如需要cookie,编码问题等等 //这是就要具体问题具体分析比如在头部加入cookie // webclient.Headers.Add("Cookie", cookie); //这样可能需要一些重载方法.根据需要写就可以了 //获取或设置用于对向 Internet 资源的请求进行身份验证的网络凭据. myWebClient.Credentials = CredentialCache.DefaultCredentials; //如果服务器要验证用户名,密码 //NetworkCredential mycred = new NetworkCredential(struser, strpassword); //myWebClient.Credentials = mycred; //从资源下载数据并返回字节数组.(加@是因为网址中间有"/"符号) byte[] myDataBuffer = myWebClient.DownloadData(url); string strWebData = Encoding.Default.GetString(myDataBuffer); //获取网页字符编码描述信息 Match charSetMatch = Regex.Match(strWebData, "<meta([^<]*)charset=([^<]*)", RegexOptions.IgnoreCase | RegexOptions.Multiline); string webCharSet = charSetMatch.Groups[2].Value; if (charSet == null || charSet == "") charSet = webCharSet; if (charSet != null && charSet != "" && Encoding.GetEncoding(charSet) != Encoding.Default) { strWebData = Encoding.GetEncoding(charSet).GetString(myDataBuffer); } else { strWebData = Encoding.GetEncoding("utf-8").GetString(myDataBuffer); } return strWebData; } catch (Exception e) { return ""; } }
第4种:类似第2种,增加了代理功能
/// <summary> /// 远程获取数据 /// </summary> /// <param name="url">url</param> /// <param name="code">编码</param> /// <param name="ProxyStr">代理IP,格式:10.20.30.40:8888</param> /// <returns></returns> public static string SendUrl(string url, Encoding code, string ProxyStr) { string html = string.Empty; //try //{ HttpWebRequest WebReques = (HttpWebRequest)HttpWebRequest.Create(url); WebReques.Method = "GET"; WebReques.Timeout = 20000; if (ProxyStr.Length > 0) { WebProxy proxy = new WebProxy(ProxyStr, true); WebReques.Proxy = proxy; } HttpWebResponse WebRespon = (HttpWebResponse)WebReques.GetResponse(); if (WebRespon != null) { StreamReader sr = new StreamReader(WebRespon.GetResponseStream(), code); html = sr.ReadToEnd(); sr.Close(); sr.Dispose(); WebRespon.Close(); } //} //catch //{ //} return html; }
第5种:gzip
public string SendUrlGZIP(string PageUrl, System.Text.Encoding encode, string ProxyStr) { HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(PageUrl); if (ProxyStr.Length > 0) { WebProxy proxy = new WebProxy(ProxyStr, true); request.Proxy = proxy; } request.Headers.Add("Accept-Encoding", "gzip,deflate"); request.AutomaticDecompression = DecompressionMethods.GZip; //request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip; WebResponse response = request.GetResponse(); Stream resStream = response.GetResponseStream(); Encoding enc = encode; StreamReader sr = new StreamReader(resStream, enc); string strHtml = sr.ReadToEnd(); resStream.Close(); sr.Close(); return strHtml; }
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