Html没有使用Html Agility Pack进行更新

时间：2014-09-11 10:13:24

标签： c# html html-agility-pack

我正在尝试从一段html中删除img和map元素。 

HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(html);

var oldHtml = doc.DocumentNode.InnerHtml;

if (doc.DocumentNode.SelectNodes("//img[@usemap]") != null)
{
    HtmlNode img = doc.DocumentNode.SelectSingleNode("//img[@usemap]");
    img.ParentNode.RemoveChild(img);
}

if (doc.DocumentNode.SelectNodes("//map") != null)
{
    HtmlNode map = doc.DocumentNode.SelectSingleNode("//map");
    map.ParentNode.RemoveChild(map);
}

var newHtml = doc.DocumentNode.InnerHtml;

newHtml仍然包含img和map元素。在更新html之前，我是否需要做其他事情？

这是我试图删除的HTML：

<p><img src="/media/8301/HD00_498x299.jpg"  width="498"  height="299" alt="HD00.JPG" usemap="#imgmap201392714219"/><br />
<br />
 <a title="Download ZIP DWG"
href="/media/8103/detailtekeningen-dwg-unidek-aero.zip"
target="_blank">Klik hier om alle DWG&nbsp;bestanden in
een&nbsp;zipfile te downloaden.</a><br />
 <a title="Download DXF"
href="/media/8104/detailtekeningen-dxf-unidek-aero.zip"
target="_blank">Klik hier om alle DXF bestanden in een zipfile te
downloaden.</a><br />
 <a title="Download PDF"
href="/media/8116/detailtekeningen-pdf-unidek-aero.zip"
target="_blank">Klik hier om alle PDF bestanden in een zipfile te
downloaden.</a><br />
<br />
 <strong><a title="Bouwdetails berekende psi-waarden"
href="/{localLink:8014}" target="_blank">Link naar de technische
bouwdetails met verbeterde eigen ψ-waarden<br />
</a></strong> &nbsp;<map name="imgmap2012104102243"
id="imgmap2012104102243">
<area title="" href="/nl/producten/hellend-dak/unidek-aero/1"
shape="rect" coords="194,419,219,439" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/2"
shape="rect" coords="221,420,246,439" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/3"
shape="rect" coords="200,302,226,320" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/4"
shape="rect" coords="209,167,234,185" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/6"
shape="rect" coords="68,46,98,67" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/7"
shape="rect" coords="102,203,129,224" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/8"
shape="rect" coords="273,339,302,360" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/9"
shape="rect" coords="387,350,417,372" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/10"
shape="rect" coords="324,341,354,363" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/11"
shape="rect" coords="223,369,252,390" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/12"
shape="rect" coords="62,270,89,294" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/13"
shape="rect" coords="93,270,119,294" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/14"
shape="rect" coords="31,94,60,114" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/14"
shape="rect" coords="79,161,106,182" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/15"
shape="rect" coords="19,150,50,171" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/15"
shape="rect" coords="82,113,110,134" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/16"
shape="rect" coords="176,231,205,253" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/17"
shape="rect" coords="147,179,176,200" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/18"
shape="rect" coords="139,235,166,257" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/19"
shape="rect" coords="204,56,231,78" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/20"
shape="rect" coords="125,135,153,157" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/21"
shape="rect" coords="265,263,290,284" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/23"
shape="rect" coords="9,202,36,225" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/24"
shape="rect" coords="39,202,65,225" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/25"
shape="rect" coords="158,80,184,101" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/26"
shape="rect" coords="188,80,213,102" target="_blank" alt="" />
</map><map id="imgmap201392714219">
<area title="" href="/nl/producten/hellend-dak/unidek-aero/1"
shape="rect" coords="265,463,279,480" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/2"
shape="rect" coords="282,466,297,480" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/3"
shape="rect" coords="213,339,237,358" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/4"
shape="rect" coords="206,204,227,220" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/6"
shape="rect" coords="113,105,135,121" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/7"
shape="rect" coords="134,246,154,262" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/8"
shape="rect" coords="299,369,319,386" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/9"
shape="rect" coords="432,409,453,425" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/10"
shape="rect" coords="363,394,385,413" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/11"
shape="rect" coords="254,406,276,422" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/12"
shape="rect" coords="105,298,122,314" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/13"
shape="rect" coords="122,298,139,314" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/14"
shape="rect" coords="53,121,77,139" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/15"
shape="rect" coords="49,165,72,182" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/16"
shape="rect" coords="195,272,214,288" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/17"
shape="rect" coords="152,212,175,230" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/18"
shape="rect" coords="160,276,180,293" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/19"
shape="rect" coords="234,88,255,105" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/20"
shape="rect" coords="132,155,158,174" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/21"
shape="rect" coords="299,294,321,311" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/23"
shape="rect" coords="40,234,55,250" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/24"
shape="rect" coords="56,233,73,251" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/25"
shape="rect" coords="185,108,202,127" target="_blank" alt="" />
<area title="" href="/nl/producten/hellend-dak/unidek-aero/26"
shape="rect" coords="203,109,219,127" target="_blank" alt="" />
</map></p>

当我调试img和map元素时，但是调用RemoveChild根本不会改变html。此外，当我尝试更改属性或其他任何事情时，没有任何事情发生。

4 个答案:

答案 0 :(得分：1)

我刚刚发现HTML Agility包的错误是你只能要求.InnerHtml一次。之后，它不会更新。你要求它两次：

HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(html);

var oldHtml = doc.DocumentNode.InnerHtml;

if (doc.DocumentNode.SelectNodes("//img[@usemap]") != null)
{
    HtmlNode img = doc.DocumentNode.SelectSingleNode("//img[@usemap]");
    img.ParentNode.RemoveChild(img);
}

if (doc.DocumentNode.SelectNodes("//map") != null)
{
    HtmlNode map = doc.DocumentNode.SelectSingleNode("//map");
    map.ParentNode.RemoveChild(map);
}

var newHtml = doc.DocumentNode.InnerHtml;

如果你摆脱这一行：

var oldHtml = doc.DocumentNode.InnerHtml;

它应该工作。它似乎是HtmlAgilityPack的随机错误。

Sniffdk的解决方案有效，因为他只获得.OuterHtml一次。 HtmlUtilityPack的人需要解决这个问题。

答案 1 :(得分：0)

似乎HtmlAgilityPack在删除节点后没有更新HtmlDocument.DocumentNode.InnerHtml属性。最简单的解决方法是使用OuterHtml属性而不是InnerHtml：

var newHtml = doc.DocumentNode.OuterHtml;

到目前为止，我总是使用OuterHtml属性来检查我所做的更改是否会产生预期的结果，现在只是实现InnerHtml的这种行为。

更新：

在发布的HTML示例中，您有2个<map>个元素。您的代码只删除一个。尝试这种方法删除所有<img>和<map>节点：

if (doc.DocumentNode.SelectNodes("//img[@usemap]") != null)
{
    HtmlNodeCollection imgs = doc.DocumentNode.SelectNodes("//img[@usemap]");
    foreach (HtmlNode img in imgs)
    {
        img.ParentNode.RemoveChild(img);
    }
}

if (doc.DocumentNode.SelectNodes("//map") != null)
{
    HtmlNodeCollection maps = doc.DocumentNode.SelectNodes("//map");
    foreach (HtmlNode map in maps)
    {
        map.ParentNode.RemoveChild(map);
    }
}
var newHtml = doc.DocumentNode.OuterHtml;

<强> [.NET Fiddle demo]

答案 2 :(得分：0)

这对我有用：

var doc = new HtmlDocument();
doc.LoadHtml(html);

var root = doc.DocumentNode;
if (root != null)
{
    var replace = false;

    images = root.SelectNodes("//img[@usemap]");
    if (images != null)
    {
        foreach (var image in images)
        {
            image.ParentNode.RemoveChild(image);
        }

        replace = true;
    }

    if (replace)
    {
        html = root.OuterHtml;
    }
}

var newhtml = html;

图片将从html中删除。

答案 3 :(得分：0)

到目前为止，我需要在html敏捷包工作之前在Umbraco中执行此操作：

var documents = Document.GetDocumentsOfDocumentType(5125);
var document = documents.Where(x => x.Id == 5127).First();

var html = document.getProperty("content").Value.ToString();
html = html.Replace("\r\n", "");
html = umbraco.library.RemoveFirstParagraphTag(html);

HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(html);
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