C#自写的一个HTML解析类(类似XElement语法)

功能:

1、轻松获取指元素HTML元素。


2、可以根据属性标签进行筛选

3、返回的都是Llist强类型无需转换

 

用过XElement的都知道 用来解析XML非常的方便,但是对于HTML的格式多样化实在是没办法兼容。

所以我就写了这么一个类似XElement的 XHTMLElement

用法:


string filePath = Server.MapPath("~/file/test.htm");
      //获取HTML代码
      string mailBody = FileHelper.FileToString(filePath);

      XHtmlElement xh = new XHtmlElement(mailBody);

      //获取body的子集a标签并且class="icon"
      var link = xh.Descendants("body").ChildDescendants("a").Where(c => c.Attributes.Any(a => a.Key == "class" && a.Value == "icon")).ToList();

      //获取带href的a元素
      var links = xh.Descendants("a").Where(c => c.Attributes.Any(a => a.Key == "href")).ToList();
      foreach (var r in links)
      {
        Response.Write(r.Attributes.Single(c => c.Key == "href").Value); //出输href
      }

      //获取第一个img
      var img = xh.Descendants("img");

      //获取最近的第一个p元素以及与他同一级的其它p元素
      var ps = xh.Descendants("p");

代码:


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Text.RegularExpressions;

namespace SyntacticSugar
{
  /// 
  /// ** 描述:html解析类
  /// ** 创始时间:2015-4-23
  /// ** 修改时间:-
  /// ** 作者:sunkaixuan
  /// ** qq:610262374 欢迎交流,共同提高 ,命名语法等写的不好的地方欢迎大家的给出宝贵建议
  /// 
  public class XHtmlElement
  {
    private string _html;
    public XHtmlElement(string html)
    {
      _html = html;
    }

    /// 
    /// 获取最近的相同层级的HTML元素
    /// 
    /// 等于null为所有元素
    /// 
    public List Descendants(string elementName = null)
    {
      if (_html == null)
      {
        throw new ArgumentNullException("html不能这空!");
      }
      var allList = RootDescendants(_html);
      var reval = allList.Where(c => elementName == null || c.TagName.ToLower() == elementName.ToLower()).ToList();
      if (reval == null || reval.Count == 0)
      {
        reval = GetDescendantsSource(allList, elementName);
      }
      return reval;
    }


    /// 
    /// 获取第一级元素
    /// 
    /// 
    /// 
    public List RootDescendants(string html = null)
    {
      /*
       * 业务逻辑:
             * 1、获取第一个html标签一直找结尾标签,如果在这个过程中遇到相同的标签收尾标签就要加1
             * 2、第一个标签取到后继续第一步操作,找第2个元素 。

第N个元素 */ if (html == null) html = _html; var firstTag = Regex.Match(html, "<.+?>"); List eleList = new List(); List reval = new List(); GetElementsStringList(html, ref eleList); foreach (var r in eleList) { HtmlInfo data = new HtmlInfo(); data.OldFullHtml = r; data.SameLeveHtml = html; data.TagName = Regex.Match(r, @"(?<=s{1}|<)[a-z,A-Z]+(?=>|s)", RegexOptions.IgnoreCase).Value; data.InnerHtml = Regex.Match(r, @"(?<=>).+(?=<)", RegexOptions.Singleline).Value; var eleBegin = Regex.Match(r, "<.+?>").Value; var attrList = Regex.Matches(eleBegin, @"[a-z,A-Z]+="".+?""").Cast().Select(c => new { key = c.Value.Split('=').First(), value = c.Value.Split('=').Last().TrimEnd('"').TrimStart('"') }).ToList(); data.Attributes = new Dictionary(); if (attrList != null && attrList.Count > 0) { foreach (var a in attrList) { data.Attributes.Add(a.key, a.value); } } reval.Add(data); } return reval; } #region private private List GetDescendantsSource(List allList, string elementName) { foreach (var r in allList) { if (r.InnerHtml == null || !r.InnerHtml.Contains("<")) continue; var childList = RootDescendants(r.InnerHtml).Where(c => elementName == null || c.TagName.ToLower() == elementName.ToLower()).ToList(); if (childList == null || childList.Count == 0) { childList = GetDescendantsSource(RootDescendants(r.InnerHtml), elementName); if (childList != null && childList.Count > 0) return childList; } else { return childList; } } return null; } private void GetElementsStringList(string html, ref List eleList) { HtmlInfo info = new HtmlInfo(); info.TagName = Regex.Match(html, @"(?<=|s)", RegexOptions.IgnoreCase).Value; string currentTagBeginReg = @"";//获取当前标签元素开始标签正则 string currentTagEndReg = @"";//获取当前标签元素收尾标签正则 if (string.IsNullOrEmpty(info.TagName)) return; string eleHtml = ""; //情况1

//情况2 //情况3 错误格式 //情况4endif if (Regex.IsMatch(html, @"

"))//单标签 { eleHtml = Regex.Match(html, @"

").Value; } else if (!Regex.IsMatch(html, currentTagEndReg))//没有收尾 { if (Regex.IsMatch(html, @"s{0,10}", 1); } else { eleHtml = Regex.Match(html, currentTagBeginReg,RegexOptions.Singleline).Value; } } else { eleHtml = GetElementString(html, currentTagBeginReg, currentTagEndReg, 1); } try { eleList.Add(eleHtml); html = html.Replace(eleHtml, ""); html = Regex.Replace(html, @"", ""); if (!Regex.IsMatch(html, @"^s*$")) { GetElementsStringList(html, ref eleList); } } catch (Exception ex) { throw new Exception("SORRY,您的HTML格式不能解析!!!"); } } private string GetElementString(string html, string currentTagBeginReg, string currentTagEndReg, int i) { string newHtml = GetRegNextByNum(html, currentTagBeginReg, currentTagEndReg, i); var currentTagBeginMatches = Regex.Matches(newHtml, currentTagBeginReg, RegexOptions.Singleline).Cast().Select(c => c.Value).ToList(); var currentTagEndMatches = Regex.Matches(newHtml, currentTagEndReg).Cast().Select(c => c.Value).ToList(); if (currentTagBeginMatches.Count == currentTagEndMatches.Count) { //两个签标元素相等 return newHtml; } return GetElementString(html, currentTagBeginReg, currentTagEndReg, ++i); } private string GetRegNextByNum(string val, string currentTagBeginReg, string currentTagEndReg, int i) { return Regex.Match(val, currentTagBeginReg + @"((.*?)" + currentTagEndReg + "){" + i + "}?", RegexOptions.IgnoreCase | RegexOptions.Singleline).Value; } #endregion } public static class XHtmlElementExtendsion { ///

/// 获取最近的相同层级的HTML元素 /// /// 等于null为所有元素 /// public static List Descendants(this IEnumerable htmlInfoList, string elementName = null) { var html = htmlInfoList.First().InnerHtml; XHtmlElement xhe = new XHtmlElement(html); return xhe.Descendants(elementName); } /// /// 获取下级元素 /// /// /// public static List ChildDescendants(this IEnumerable htmlInfoList, string elementName = null) { var html = htmlInfoList.First().InnerHtml; XHtmlElement xhe = new XHtmlElement(html); return xhe.RootDescendants(html).Where(c => elementName == null || c.TagName == elementName).ToList(); } /// /// 获取父级 /// /// /// public static List ParentDescendant(this IEnumerable htmlInfoList,string fullHtml) { var saveLeveHtml = htmlInfoList.First().SameLeveHtml; string replaceGuid=Guid.NewGuid().ToString(); fullHtml = fullHtml.Replace(saveLeveHtml,replaceGuid); var parentHtml = Regex.Match(fullHtml, @"<[^<]+?>[^<]*?" + replaceGuid + @".*?").Value; parentHtml = parentHtml.Replace(replaceGuid, saveLeveHtml); XHtmlElement xhe = new XHtmlElement(parentHtml); return xhe.RootDescendants(); } } /// /// html信息类 /// public class HtmlInfo { /// /// 元素名 /// public string TagName { get; set; } /// /// 元素属性 /// public Dictionary Attributes { get; set; } /// /// 元素内部html /// public string InnerHtml { get; set; } public string OldFullHtml { get; set; } public string SameLeveHtml { get; set; } /// /// 得到元素的html /// /// public string FullHtml { get { StringBuilder reval = new StringBuilder(); string attributesString = string.Empty; if (Attributes != null && Attributes.Count > 0) { attributesString = string.Join(" ", Attributes.Select(c => string.Format("{0}="{1}"", c.Key, c.Value))); } reval.AppendFormat("<{0} {2}>{1}", TagName, InnerHtml, attributesString); return reval.ToString(); } } } }

前台HTML:

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