解析时的html敏捷包问题

时间:2010-06-24 20:13:52

标签: c# asp.net html-agility-pack

我有这个简单的字符串:

string testString = "6/21 <span style='font-size: x-small; font-family: Arial'><span style='font-size: 10pt; font-family: Arial'>Just got 78th street</span></span>";

如何使用html敏捷包来解析文本。

请注意:在另一个范围内嵌套了一个跨度。

感谢, 杆

2 个答案:

答案 0 :(得分:1)

我认为InnertText属性应该只提供文本 -

var testString = "6/21 <span style='font-size: x-small; font-family: Arial'><span style='font-size: 10pt; font-family: Arial'>Just got 78th street</span></span>";
var doc = new HtmlDocument();
doc.LoadHtml(testString);
var justTheText = doc.DocumentNode.InnerText;

此代码将返回 -

6/21 Just got 78th street

这就是你想要的吗?

答案 1 :(得分:1)

另一种方法是使用Sanitizer类删除您不想要的标记,同时保留文本。

public static class HtmlSanitizer
    {
        private static readonly IDictionary<string, string[]> Whitelist;
        private static List<string> DeletableNodesXpath = new List<string>();

        static HtmlSanitizer()
        {
            Whitelist = new Dictionary<string, string[]> {
                { "a", new[] { "href" } },
                { "strong", null },
                { "em", null },
                { "blockquote", null },
                { "b", null},
                { "p", null},
                { "ul", null},
                { "ol", null},
                { "li", null},
                { "div", new[] { "align" } },
                { "strike", null},
                { "u", null},                
                { "sub", null},
                { "sup", null},
                { "table", null },
                { "tr", null },
                { "td", null },
                { "th", null }
                };
        }

        public static string Sanitize(string input)
        {
            if (input.Trim().Length < 1)
                return string.Empty;
            var htmlDocument = new HtmlDocument();

            htmlDocument.LoadHtml(input);            
            SanitizeNode(htmlDocument.DocumentNode);
            string xPath = HtmlSanitizer.CreateXPath();

            return StripHtml(htmlDocument.DocumentNode.WriteTo().Trim(), xPath);
        }

        private static void SanitizeChildren(HtmlNode parentNode)
        {
            for (int i = parentNode.ChildNodes.Count - 1; i >= 0; i--)
            {
                SanitizeNode(parentNode.ChildNodes[i]);
            }
        }

        private static void SanitizeNode(HtmlNode node)
        {
            if (node.NodeType == HtmlNodeType.Element)
            {
                if (!Whitelist.ContainsKey(node.Name))
                {
                    if (!DeletableNodesXpath.Contains(node.Name))
                    {                       
                        //DeletableNodesXpath.Add(node.Name.Replace("?",""));
                        node.Name = "removeableNode";
                        DeletableNodesXpath.Add(node.Name);
                    }
                    if (node.HasChildNodes)
                    {
                        SanitizeChildren(node);
                    }                  

                    return;
                }

                if (node.HasAttributes)
                {
                    for (int i = node.Attributes.Count - 1; i >= 0; i--)
                    {
                        HtmlAttribute currentAttribute = node.Attributes[i];
                        string[] allowedAttributes = Whitelist[node.Name];
                        if (allowedAttributes != null)
                        {
                            if (!allowedAttributes.Contains(currentAttribute.Name))
                            {
                                node.Attributes.Remove(currentAttribute);
                            }
                        }
                        else
                        {
                            node.Attributes.Remove(currentAttribute);
                        }
                    }
                }
            }

            if (node.HasChildNodes)
            {
                SanitizeChildren(node);
            }
        }

        private static string StripHtml(string html, string xPath)
        {
            HtmlDocument htmlDoc = new HtmlDocument();
            htmlDoc.LoadHtml(html);
            if (xPath.Length > 0)
            {
                HtmlNodeCollection invalidNodes = htmlDoc.DocumentNode.SelectNodes(@xPath);
                foreach (HtmlNode node in invalidNodes)
                {
                    node.ParentNode.RemoveChild(node, true);
                }
            }
            return htmlDoc.DocumentNode.WriteContentTo(); ;
        }

        private static string CreateXPath()
        {
            string _xPath = string.Empty;
            for (int i = 0; i < DeletableNodesXpath.Count; i++)
            {
                if (i != DeletableNodesXpath.Count - 1)
                {
                    _xPath += string.Format("//{0}|", DeletableNodesXpath[i].ToString());
                }
                else _xPath += string.Format("//{0}", DeletableNodesXpath[i].ToString());
            }
            return _xPath;
        }
    }

它很容易。我采取了白名单的方式。因此,只需删除您不想要的所有标记和属性。使用HtmlSanitizer.Sanitize(@html)