HtmlAgilityPack 将 <（小于号）之后的所有内容都视为属性

Question

我有一些通过文本区域获得的输入，我将该输入转换为 html 文档，稍后将其解析为 PDF 文档。

当我的用户输入小于号 (<) 时，我的 HtmlDocument 中的一切都停止了。 HtmlAgilityPack 突然将小于号之后的所有内容都作为属性处理。查看输出：

Within this Character Data block I can use double dashes as much as I want (along with <, &,="" ',="" and="" ')="" *and="" *="" %="" myparamentity;="" will="" be="" expanded="" to="" the="" text="" 'has="" been="" expanded'...however,="" i="" can't="" use="" the="" cend="" sequence(if="" i="" need="" to="" use="" it="" i="" must="" escape="" one="" of="" the="" brackets="" or="" the="" greater-than="" sign).="">

如果我加上

会好一点

htmlDocument.OptionOutputOptimizeAttributeValues = true;

这给了我：

Within this Character Data block I can use double dashes as much as I want (along with <, &,= ',= and= ')= *and= *= %= myparamentity;= will= be= expanded= to= the= text= 'has= been= expanded'...however,= i= can't= use= the= cend= sequence(if= i= need= to= use= it= i= must= escape= one= of= the= brackets= or= the= greater-than= sign).=>

我已经尝试了 html 文档中的所有选项，其中 none 让我指定解析器不应该是严格的。另一方面，我可能可以忍受它去掉 <，但是添加所有等号对我来说真的不起作用。

void Main()
{
    var input = @"Within this Character Data block I can use double dashes as much as I want (along with <, &, ', and ') *and * % MyParamEntity; will be expanded to the text 'Has been expanded'...however, I can't use the CEND sequence(if I need to use it I must escape one of the brackets or the greater-than sign).";

    var htmlDoc = WrapContentInHtml(input);

    htmlDoc.DocumentNode.OuterHtml.ToString().Dump();
}

private HtmlDocument WrapContentInHtml(string content)
{
    var htmlBuilder = new StringBuilder();
    htmlBuilder.AppendLine("<!DOCTYPE html>");
    htmlBuilder.AppendLine("<html>");
    htmlBuilder.AppendLine("<head>");
    htmlBuilder.AppendLine("<title></title>");
    htmlBuilder.AppendLine("</head>");
    htmlBuilder.AppendLine("<body><div id='sagsfremstillingContainer'>");
    htmlBuilder.AppendLine(content); 
    htmlBuilder.AppendLine("</div></body></html>");

    var htmlDocument = new HtmlDocument();
    htmlDocument.OptionOutputOptimizeAttributeValues = true;
    var htmlDoc = htmlBuilder.ToString();

    htmlDocument.LoadHtml(htmlDoc);

    return htmlDocument;
}

有没有人知道我该如何解决这个问题。

我能找到的最接近的问题是： Losing the 'less than' sign in HtmlAgilityPack loadhtml

他实际上抱怨 < 消失，这对我来说没问题。当然修复解析错误是最好的解决办法。

编辑：我正在使用 HtmlAgilityPack 1.4.9

Answer 1

您的内容明显错误。这不是关于 "strictness"，而是关于你假装一段文本是有效的事实 HTML。事实上，你得到的结果正是因为解析器 not strict.

当你需要在HTML中插入纯文本时，你需要先对其进行编码，以便将所有各种HTML控制字符正确转换为HTML——例如, < 必须更改为 < 并且 & 必须更改为 &.

处理此问题的一种方法是使用 DOM - 在目标 div 上使用 InnerText，而不是将字符串拍打在一起并假装它们是 HTML .另一种是使用一些显式编码方法——例如 HttpUtility.HtmlEncode.

Answer 2

您可以使用System.Net.WebUtility.HtmlEncode which works even without a reference to System.Web.dll which also has HttpServerUtility.HtmlEncode

var input = @"Within this Character Data block I can use double dashes as much as I want (along with <, &, ', and ') *and * % MyParamEntity; will be expanded to the text 'Has been expanded'...however, I can't use the CEND sequence(if I need to use it I must escape one of the brackets or the greater-than sign).";
var htmlDocument = new HtmlDocument();
htmlDocument.LoadHtml(System.Net.WebUtility.HtmlEncode(input));
Debug.Assert(!htmlDocument.ParseErrors.Any());

结果：

Within this Character Data block I can use double dashes as much as I want (along with &lt;, &amp;, &#39;, and &#39;) *and * % MyParamEntity; will be expanded to the text &#39;Has been expanded&#39;...however, I can&#39;t use the CEND sequence(if I need to use it I must escape one of the brackets or the greater-than sign).

HtmlAgilityPack 将 <（小于号）之后的所有内容都视为属性

HtmlAgilityPack treats everything after < (less than sign) as attributes

c#

html-agility-pack