关键代码：
1 private Hashtable hash;//储存代理ip 2 private WebProxy currentdaili; 3 private int dailiExecMaxCount; //每个代理执行最大次数 4 private int currentDailiExecCount; //当前代理执行次数 5 public Handler2() //构造函数 6 { 7 dailiExecMaxCount = 100; 8 currentDailiExecCount = 0; 9 //hash = GetDailiList(); 10 currentdaili = GetOneDaili(); 11 } 12 13 14 //http://www.xici.net.co 15 /// <summary> 16 /// 获取代理ip返回hashtable 17 /// KK 2015-04-22 18 /// </summary> 19 /// <returns></returns> 20 private Hashtable GetDailiList() 21 { 22 Hashtable result = new Hashtable(); 23 string strUrl = string.Format("http://www.xici.net.co"); 24 string detailContext = GetHtmlByUrl(strUrl); 25 if (!string.IsNullOrEmpty(detailContext)) 26 { 27 HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument(); 28 string strkeyvalue = string.Empty; 29 try 30 { 31 doc.LoadHtml(detailContext); 32 HtmlNode node = doc.DocumentNode; 33 HtmlNodeCollection trlist = node.SelectNodes("//table[@id='ip_list']//tr[@class='odd' or @class='']"); 34 foreach (HtmlNode item in trlist) 35 { 36 if (item.SelectNodes("td")[5].InnerText.ToUpper() == "HTTP") 37 { 38 strkeyvalue = item.SelectNodes("td")[1].InnerText + ":" + item.SelectNodes("td")[2].InnerText; 39 result.Add(strkeyvalue, strkeyvalue); 40 } 41 } 42 } 43 catch (Exception ex) 44 { 45 webframework.common.logclass.Debug("======取代理ip出错====GetDaili==" + ex.Message); 46 result = null; 47 } 48 49 50 } 51 else 52 { 53 result = null; 54 } 55 return result; 56 } 57 58 /// <summary> 59 /// 从hashtable代理中取任意ip代理 60 /// </summary> 61 /// <param name="hash"></param> 62 /// <returns></returns> 63 private WebProxy GetOneDaili() 64 { 65 try 66 { 67 if (hash == null || hash.Count == 0) 68 hash = GetDailiList(); 69 if (currentdaili != null && hash.Contains(currentdaili.Address.Authority + ":" + currentdaili.Address.Port)) 70 { 71 hash.Remove(currentdaili.Address.Authority + ":" + currentdaili.Address.Port); 72 } 73 System.Collections.IDictionaryEnumerator enumerator = hash.GetEnumerator(); 74 75 //随机取代理 76 Random rd = new Random(); 77 int n = rd.Next(hash.Count); 78 int intCount = 0; 79 while (enumerator.MoveNext()) 80 { 81 intCount++; 82 if (intCount == n) 83 { 84 currentdaili = new WebProxy(enumerator.Key.ToString(), true); 85 break; 86 } 87 } 88 } 89 catch (Exception ex) 90 { 91 webframework.common.logclass.Debug("======从hashtable代理中取任意ip代理出错====GetOneDaili==" + ex.Message); 92 currentdaili = null; 93 } 94 logclass.Debug("======当前代理======" + currentdaili.Address.Authority + ":" + currentdaili.Address.Port ); 95 return currentdaili; 96 }
使用：
1 /// <summary> 2 /// 发送get请求 3 /// </summary> 4 /// <param name="strUrl"></param> 5 /// <param name="isRetry"></param> 6 /// <returns></returns> 7 private string GetHtmlByUrl(string strUrl, bool isRetry = false, WebProxy daili = null) 8 { 9 currentDailiExecCount++; 10 if (currentDailiExecCount > dailiExecMaxCount) 11 { 12 logclass.Debug("======当前代理======" + currentdaili.Address.Authority + ":" + currentdaili.Address.Port + "==跑的次数超过了设置的最大次数（" + dailiExecMaxCount.ToString()+"）"); 13 } 14 try 15 { 16 HttpWebResponse response = new webframework.common.HttpHelper() 17 { 18 URL = string.Format("{0}", strUrl), 19 //Proxy = daili == null ? currentdaili : daili, 20 //Proxy = new WebProxy("218.204.140.97:8118", true), 21 Proxy = daili == null ? (currentDailiExecCount > dailiExecMaxCount ? GetOneDaili() : currentdaili) : daili, 22 Timeout = 5 * 1000, 23 }.CreateGetHttpResponse(); 24 25 return response.HttpString(Encoding.UTF8); 26 } 27 catch (Exception) 28 { 29 //重试请求 30 if (!isRetry) 31 return GetHtmlByUrl(strUrl, true, GetOneDaili()); 32 else 33 throw null; 34 } 35 36 } 37 38 39 /// <summary> 40 /// 发送post请求 41 /// </summary> 42 /// <param name="strUrl"></param> 43 /// <param name="isRetry"></param> 44 /// <returns></returns> 45 private string PostHtmlByUrl(string strUrl, string strPostString, bool isRetry = false, WebProxy daili = null) 46 { 47 currentDailiExecCount++; 48 if (currentDailiExecCount > dailiExecMaxCount) 49 { 50 logclass.Debug("======当前代理======" + currentdaili.Address.Authority + ":" + currentdaili.Address.Port + "==跑的次数超过了设置的最大次数（" + dailiExecMaxCount.ToString()+"）"); 51 } 52 try 53 { 54 HttpWebResponse response = new HttpHelper() 55 { 56 URL = strUrl, 57 PostString = strPostString, 58 //Proxy = new WebProxy("218.204.140.97:8118", true), 59 Proxy = daili == null ? (currentDailiExecCount>dailiExecMaxCount?GetOneDaili(): currentdaili) : daili, 60 //Proxy = daili == null ? currentdaili : daili, 61 PostEncoding = Encoding.UTF8, 62 Timeout = 5 * 1000, 63 }.CreatePostHttpResponse(); 64 65 return response.HttpString(Encoding.UTF8); 66 } 67 catch (Exception) 68 { 69 //重试请求 70 if (!isRetry) 71 return PostHtmlByUrl(strUrl, strPostString, true, GetOneDaili()); 72 else 73 throw null; 74 } 75 76 }
参考资料：
http://www.haolizi.net/example/view_199.html