使用 Agility Pack 从 HTML 中删除所有已指定类的元素
我试图选择具有给定类的所有元素并将它们从 HTML 字符串中删除。
这是我到目前为止所拥有的，尽管源代码清楚地显示了具有该类名称的 4 个元素，但它似乎没有删除任何内容。
// Filter page HTML to display required content
HtmlAgilityPack.HtmlDocument htmlDoc = new HtmlAgilityPack.HtmlDocument();
// filePath is a path to a file containing the html
htmlDoc.LoadHtml(pageHTML);
// ParseErrors is an ArrayList containing any errors from the Load statement);
if (!htmlDoc.ParseErrors.Any())
{
// Remove all elements marked with pdf-ignore class
HtmlNodeCollection nodes = htmlDoc.DocumentNode.SelectNodes("//body[@class='pdf-ignore']");
// Remove the collection from above
foreach (var node in nodes)
{
node.Remove();
}
}
编辑：只是为了澄清文档正在解析并且 SelectNodes 行正在被命中，只是不返回任何内容。
这是 html 的一个片段：
<input type=\"submit\" name=\"ctl00$MainContent$PrintBtn\" value=\"Print Shotlist\" onclick=\"window.print();\" id=\"MainContent_PrintBtn\" class=\"pdf-ignore\">
I'm trying to select all elements that have a given class and remove them from a HTML string.
This is what I have so far it doesn't seem to remove anything although the source shows clearly 4 elements with that class name.
// Filter page HTML to display required content
HtmlAgilityPack.HtmlDocument htmlDoc = new HtmlAgilityPack.HtmlDocument();
// filePath is a path to a file containing the html
htmlDoc.LoadHtml(pageHTML);
// ParseErrors is an ArrayList containing any errors from the Load statement);
if (!htmlDoc.ParseErrors.Any())
{
// Remove all elements marked with pdf-ignore class
HtmlNodeCollection nodes = htmlDoc.DocumentNode.SelectNodes("//body[@class='pdf-ignore']");
// Remove the collection from above
foreach (var node in nodes)
{
node.Remove();
}
}
EDIT: Just to clarify the document is parsing and the SelectNodes line is being hit, just not returning anything.
Here is a snippet of the html:
<input type=\"submit\" name=\"ctl00$MainContent$PrintBtn\" value=\"Print Shotlist\" onclick=\"window.print();\" id=\"MainContent_PrintBtn\" class=\"pdf-ignore\">
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编辑：在更新后的答案中，您将 HTML 字符串的一部分发布为
元素声明，但您试图匹配;类pdf-ignore元素（根据您的表达式//body[@class='pdf-ignore']）。如果您想将文档中的所有元素与此类匹配，您应该使用：
code 来获取节点。这将匹配具有指定类名的所有元素。
除了一个细节之外，您的代码似乎是正确的：条件
htmlDoc.ParseErrors == null。仅当ParseErrors属性（这是IEnumerable的类型）为null时才选择并删除节点，但实际上如果没有错误发现这个属性返回一个空列表。因此，将代码更改为：应该可以解决问题。
EDIT: in your updated answer you posted a part of the HTML string an
<input>element declaration, but you're trying to match a<body>element with the classpdf-ignore(according to your expression//body[@class='pdf-ignore']).If you want to match all the elements from the document with this class you should use:
code to get your nodes. This will match all the elements with the class name specified.
Your code is seems to be correct except the one detail: the condition
htmlDoc.ParseErrors == null. You select and remove nodes ONLY if theParseErrorsproperty (which is a type ofIEnumerable<HtmlParseError>) isnull, but actually if no errors found this property returns an empty list. So changing your code to:should solve the issue.
您的 xpath 可能不匹配：您是否尝试过
"//div[class='pdf-ignore']"（没有"@"）？Your xpath is probably not matching: have you tried
"//div[class='pdf-ignore']"(no"@")?