Question

我通过textarea获得了一些输入，并将该输入转换为html文档，稍后将其解析为PDF文档。

当我的用户输入小于号（＆lt;）时，我的HtmlDocument中的所有内容都会刹车。 HtmlAgilityPack突然处理少于符号作为属性后的所有内容。见输出：

在这个字符数据块中，我可以根据需要使用双短划线（连同＆lt;，＆amp;，=＆＃34;＆＃34;＆＃39;，=＆＃34;＆＃34;和=＆＃34;＆＃34;＆＃39;）=＆＃34;＆＃34; *和=＆＃34;＆＃34; * =＆＃34;＆＃34; （％）=＆＃34;＆＃34; myparamentity; =＆＃34;＆＃34;将=＆＃34;＆＃34;是=＆＃34;＆＃34;扩展=＆＃34;＆＃34;到=＆＃34;＆＃34;的=＆＃34;＆＃34;文本=＆＃34;＆＃34; ＆＃39;具有=＆＃34;＆＃34;一直=＆＃34;＆＃34;扩大＆＃39; ...然而，=＆＃34;＆＃34; I =＆＃34;＆＃34;可＆＃39; T =＆＃34;＆＃34;使用=＆＃34;＆＃34;的=＆＃34;＆＃34; CEND =＆＃34;＆＃34;序列（if =＆＃34;＆＃34; i =＆＃34;＆＃34; need =＆＃34;＆＃34; to =＆＃34;＆＃34; use =＆＃34;＆＃ 34;它=＆＃34;＆＃34; i =＆＃34;＆＃34;必须=＆＃34;＆＃34;逃避=＆＃34;＆＃34;一个=＆＃34;＆＃ 34; of =＆＃34;＆＃34; =＆＃34;＆＃34;括号=＆＃34;＆＃34;或=＆＃34;＆＃34; =＆＃34;＆＃ 34;大于=＆＃34;＆＃34;签署）。=＆＃34;＆＃34;＆gt;

如果我只是添加

，它会好一点

htmlDocument.OptionOutputOptimizeAttributeValues = true;

给了我：

在这个字符数据块中，我可以根据需要使用双破折号（以及＆lt;，＆amp;，=＆＃39;，=和=＆＃39;）= *和= * =％= myparamentity; =将= be = expanded = to = the = text =＆＃39; has = been = expanded＆＃39; ...但是，= i = can＆＃39; t = use = the = cend = sequence（if = i = need = to = use = it = i = must = escape = one = of = the = bracket = or = the = greater-than = sign）。=＆gt;

我已经尝试了htmldocument上的所有选项，但没有一个让我指定解析器不应该是严格的。另一方面，我可以忍受它剥离＆lt;，但添加所有等号并不适合我。

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＆lt;消失对我来说没问题。当然，修复解析错误是最佳解决方案。

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“严格”，它实际上是关于你假装一段文本是有效的HTML的事实。事实上，您获得的结果正是因为解析器不严格。

当您需要将纯文本插入HTML时，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< }和&到&。

处理此问题的一种方法是使用DOM - 在目标InnerText上使用div，而不是将字符串拼接在一起并假装它们是HTML。另一种方法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，即使没有System.Web.dll也有HttpServerUtility.HtmlEncode

的引用

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在＆lt;之后处理所有内容（小于号）作为属性

2 个答案: