C#收集爬蟲代碼分享 C#簡略的爬取對象。本站提示廣大學習愛好者：（C#收集爬蟲代碼分享 C#簡略的爬取對象）文章只能為提供參考，不一定能成為您想要的結果。以下是C#收集爬蟲代碼分享 C#簡略的爬取對象正文
公司編纂妹子須要爬取網頁內容，叫我協助做了一簡略的爬取對象
這是爬取網頁內容，像是這對年夜家來講都是不可貴，然則在這裡有一些小修改，代碼獻上，年夜家參考
private string GetHttpWebRequest(string url)
{
HttpWebResponse result;
string strHTML = string.Empty;
try
{
Uri uri = new Uri(url);
WebRequest webReq = WebRequest.Create(uri);
WebResponse webRes = webReq.GetResponse();
HttpWebRequest myReq = (HttpWebRequest)webReq;
myReq.UserAgent = "User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705";
myReq.Accept = "*/*";
myReq.KeepAlive = true;
myReq.Headers.Add("Accept-Language", "zh-cn,en-us;q=0.5");
result = (HttpWebResponse)myReq.GetResponse();
Stream receviceStream = result.GetResponseStream();
StreamReader readerOfStream = new StreamReader(receviceStream, System.Text.Encoding.GetEncoding("utf-8"));
strHTML = readerOfStream.ReadToEnd();
readerOfStream.Close();
receviceStream.Close();
result.Close();
}
catch
{
Uri uri = new Uri(url);
WebRequest webReq = WebRequest.Create(uri);
HttpWebRequest myReq = (HttpWebRequest)webReq;
myReq.UserAgent = "User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705";
myReq.Accept = "*/*";
myReq.KeepAlive = true;
myReq.Headers.Add("Accept-Language", "zh-cn,en-us;q=0.5");
//result = (HttpWebResponse)myReq.GetResponse();
try
{
result = (HttpWebResponse)myReq.GetResponse();
}
catch (WebException ex)
{
result = (HttpWebResponse)ex.Response;
}
Stream receviceStream = result.GetResponseStream();
StreamReader readerOfStream = new StreamReader(receviceStream, System.Text.Encoding.GetEncoding("gb2312"));
strHTML = readerOfStream.ReadToEnd();
readerOfStream.Close();
receviceStream.Close();
result.Close();
}
return strHTML;
}
這是依據url爬取網頁遠嗎，有一些小修改，許多網頁有分歧的編碼格局，乃至有些網站做了反爬取的防備，這個辦法經由可以或許修改也能爬去
以下是爬取網頁一切的網址鏈接
/// <summary>
/// 提取HTML代碼中的網址
/// </summary>
/// <param name="htmlCode"></param>
/// <returns></returns>
private static List<string> GetHyperLinks(string htmlCode, string url)
{
ArrayList al = new ArrayList();
bool IsGenxin = false;
StringBuilder weburlSB = new StringBuilder();//SQL
StringBuilder linkSb = new StringBuilder();//展現數據
List<string> Weburllistzx = new List<string>();//新增
List<string> Weburllist = new List<string>();//舊的
string ProductionContent = htmlCode;
Regex reg = new Regex(@"http(s)?://([\w-]+\.)+[\w-]+/?");
string wangzhanyuming = reg.Match(url, 0).Value;
MatchCollection mc = Regex.Matches(ProductionContent.WordStr("href=\"/", "href=\"" + wangzhanyuming).WordStr("href='/", "href='" + wangzhanyuming).WordStr("href=/", "href=" + wangzhanyuming).WordStr("href=\"./", "href=\"" + wangzhanyuming), @"<[aA][^>]* href=[^>]*>", RegexOptions.Singleline);
int Index = 1;
foreach (Match m in mc)
{
MatchCollection mc1 = Regex.Matches(m.Value, @"[a-zA-z]+://[^\s]*", RegexOptions.Singleline);
if (mc1.Count > 0)
{
foreach (Match m1 in mc1)
{
string linkurlstr = string.Empty;
linkurlstr = m1.Value.WordStr("\"", "").WordStr("'", "").WordStr(">", "").WordStr(";", "");
weburlSB.Append("$-$");
weburlSB.Append(linkurlstr);
weburlSB.Append("$_$");
if (!Weburllist.Contains(linkurlstr) && !Weburllistzx.Contains(linkurlstr))
{
IsGenxin = true;
Weburllistzx.Add(linkurlstr);
linkSb.AppendFormat("{0}<br/>", linkurlstr);
}
}
}
else
{
if (m.Value.IndexOf("javascript") == -1)
{
string amstr = string.Empty;
string wangzhanxiangduilujin = string.Empty;
wangzhanxiangduilujin = url.Substring(0, url.LastIndexOf("/") + 1);
amstr = m.Value.WordStr("href=\"", "href=\"" + wangzhanxiangduilujin).WordStr("href='", "href='" + wangzhanxiangduilujin);
MatchCollection mc11 = Regex.Matches(amstr, @"[a-zA-z]+://[^\s]*", RegexOptions.Singleline);
foreach (Match m1 in mc11)
{
string linkurlstr = string.Empty;
linkurlstr = m1.Value.WordStr("\"", "").WordStr("'", "").WordStr(">", "").WordStr(";", "");
weburlSB.Append("$-$");
weburlSB.Append(linkurlstr);
weburlSB.Append("$_$");
if (!Weburllist.Contains(linkurlstr) && !Weburllistzx.Contains(linkurlstr))
{
IsGenxin = true;
Weburllistzx.Add(linkurlstr);
linkSb.AppendFormat("{0}<br/>", linkurlstr);
}
}
}
}
Index++;
}
return Weburllistzx;
}
這塊的技巧其實就是簡略的應用了正則去婚配！接上去獻上獲得題目，和存儲到xml文件的辦法
/// <summary>
/// // 把網址寫入xml文件
/// </summary>
/// <param name="strURL"></param>
/// <param name="alHyperLinks"></param>
private static void WriteToXml(string strURL, List<string> alHyperLinks)
{
XmlTextWriter writer = new XmlTextWriter(@"D:\HyperLinks.xml", Encoding.UTF8);
writer.Formatting = Formatting.Indented;
writer.WriteStartDocument(false);
writer.WriteDocType("HyperLinks", null, "urls.dtd", null);
writer.WriteComment("提取自" + strURL + "的超鏈接");
writer.WriteStartElement("HyperLinks");
writer.WriteStartElement("HyperLinks", null);
writer.WriteAttributeString("DateTime", DateTime.Now.ToString());
foreach (string str in alHyperLinks)
{
string title = GetDomain(str);
string body = str;
writer.WriteElementString(title, null, body);
}
writer.WriteEndElement();
writer.WriteEndElement();
writer.Flush();
writer.Close();
}
/// <summary>
/// 獲得網址的域名後綴
/// </summary>
/// <param name="strURL"></param>
/// <returns></returns>
private static string GetDomain(string strURL)
{
string retVal;
string strRegex = @"(\.com/|\.net/|\.cn/|\.org/|\.gov/)";
Regex r = new Regex(strRegex, RegexOptions.IgnoreCase);
Match m = r.Match(strURL);
retVal = m.ToString();
strRegex = @"\.|/$";
retVal = Regex.WordStr(retVal, strRegex, "").ToString();
if (retVal == "")
retVal = "other";
return retVal;
}
/// <summary>
/// 獲得題目
/// </summary>
/// <param name="html"></param>
/// <returns></returns>
private static string GetTitle(string html)
{
string titleFilter = @"<title>[\s\S]*?</title>";
string h1Filter = @"<h1.*?>.*?</h1>";
string clearFilter = @"<.*?>";
string title = "";
Match match = Regex.Match(html, titleFilter, RegexOptions.IgnoreCase);
if (match.Success)
{
title = Regex.WordStr(match.Groups[0].Value, clearFilter, "");
}
// 注釋的題目普通在h1中，比title中的題目更清潔
match = Regex.Match(html, h1Filter, RegexOptions.IgnoreCase);
if (match.Success)
{
string h1 = Regex.WordStr(match.Groups[0].Value, clearFilter, "");
if (!String.IsNullOrEmpty(h1) && title.StartsWith(h1))
{
title = h1;
}
}
return title;
}
這就是所用的全體辦法，照樣有許多須要改良的地方！年夜家假如有發明缺乏的地方還請指出，感謝！
以上就是本文的全體內容，願望對年夜家的進修有所贊助，也願望年夜家多多支撐。
