asp.net抓取html文件,asp.net 抓取网页源码三种实现方法

方法1 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

///

/// 网页地址"

/// 返回网页源文件

public static string GetHtmlSource2(string url)

{

//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 http://www.52mvc.com

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, Encoding.Default);

html = reader.ReadToEnd();

stream.Close();

return html;

}

方法2

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.IO;

using System.Text;

using System.Net;

namespace MySql

{

public class GetHttpData

{

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;

}

}

}

方法3

public static string getHtml(string url, params string [] charSets)//url是要访问的网站地址，charSet是目标网页的编码，如果传入的是null或者""，那就自动分析网页的编码

{

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, "

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 ""; }

}

asp.net 获取网页源文件的方法

有时候我们需要获取 网页源文件，所以用以下这个方法很容易完成任务！

private string GetStringByUrl(string strUrl)

{

WebRequest wrt = WebRequest.Create(strUrl);

WebResponse wrse = wrt.GetResponse();

Stream strM = wrse.GetResponseStream();

StreamReader SR = new StreamReader(strM, Encoding.GetEncoding("gb2312"));

string strallstrm = SR.ReadToEnd();

return strallstrm;

}

只要传入要下载网页的地址就OK了！

通过这个方法做个源码导出:

private string SaveHTML()

{

string str = RenderPage("Default2.aspx");

Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8"); //解决中文乱码

Response.AddHeader("Content-Disposition","attachment;filename=index.html"); //解决中文文件名乱码

Response.AddHeader("Content-length",str.Length.ToString());

Response.Write(str);

Response.End();

｝

以上就是asp.net 抓取网页源码的全部代码了，希望对大家有所帮助。