HTML 解析 C# HTML 敏捷包

Question

我在使用 HTMLAgilityPack 从 HTML 字符串读取某些值时遇到问题。

我想看的两个项目是报纸：82548828 和鱼：8545852485

但是使用我到目前为止编写的代码我只能取回报纸项目。

我怀疑我使用的 XPATH 不完全正确，我认为第一个循环的 XPATH 是正确的，因为这让我返回了两个

我希望我的第二个循环遍历这两项（它认为有 6 个？？？）

也就是div2.SelectSingleNode(sXPathT);提取groupLabel的正确方法？或者有更好的方法吗？

谢谢

下面是完整的测试代码

string strTestHTML = @"<div class=\""content\"" data-id=\""123456789\"">" + 
                              "  <div class=\"m-group item\">" +
                              "      <span class=\"group\">" +
                              "          <a href=\"javascript:void(0);\">" +
                              "          <span class=\"group-label\">Newspaper </span>" +
                              "          <span class=\"group-value\">82548828</span>" +
                              "          </a>" +
                              "      </span>" +
                              "      <span class=\"group\">" +
                              "          <a href=\"javascript:void(0);\">" +
                              "          <span class=\"group-label\">Fish </span>" +
                              "          <span class=\"group-value\">8545852485</span>" +
                              "          </a>" +
                              "      </span>" +
                              "  </div>" +
                              "</div>";


            //<div class="content" data-id="123456789">
            string sNewXpath = "//div[contains(@class,'content') and contains(@data-id, '" + "123456789" + "')]";
            //<div class="m-group item">
            string sSecondXPath = "/div[contains(@class,'m-group item')]";
            //<span class="group"
            string sThirdXPath = "//span[contains(@class,'group')]";

            string sXPathT = "//span[contains(@class,'group-label')]";
            string sXPathO = "//span[contains(@class,'group-value')]";

            HtmlAgilityPack.HtmlDocument Doc = new HtmlDocument();
            Doc.LoadHtml(strTestHTML);

            foreach (HtmlNode div in Doc.DocumentNode.SelectNodes(sNewXpath + sSecondXPath))
            {
                foreach (HtmlNode div2 in div.SelectNodes(sThirdXPath))
                {
                    var vOddL = div2.SelectSingleNode(sXPathT);
                    var vOddP = div2.SelectSingleNode(sXPathO);

                    string GroupLabel = vOddL.InnerText.Trim();

                    string GroupValue = vOddP.InnerText.Trim();
                }
            }

编辑：

弄清楚为什么我在 forloop 中得到 6 个项目

sThirdXPath 是：string sThirdXPath = "//span[contains(@class,'group')]";

应该是：

string sThirdXPath = "//span[@class='group']";

仍在尝试寻找正确的方法来询问 div2 中包含的 HTMLNode 以找到感兴趣的值。我假设它需要 XPath 来匹配当前节点内的 iinside，而不是 HTML 文档范围。

已更新 HTML 示例：

<div class="content" data-id="123456789">
<div class="m-group item">
    <span class="group">
        <a href="javascript:void(0);">
        <span class="group-label">Newspaper </span>
        <span class="group-value">82548828</span>
        </a>
    </span>

    <span class="group">
        <a href="javascript:void(0);">
        <span class="group-label">Fish </span>
        <span class="group-value">8545852485</span>
        </a>
    </span>
</div>
</div>

<div class="content" data-id="987654321">
<div class="m-group item">
    <span class="group">
        <a href="javascript:void(0);">
        <span class="group-label">Bread</span>
        <span class="group-value">82548828</span>
        </a>
    </span>

    <span class="group">
        <a href="javascript:void(0);">
        <span class="group-label">Milk </span>
        <span class="group-value">8545852485</span>
        </a>
    </span>
</div>
</div>

在上面的示例中，访问 Just Bread and Its Value 和 Milk and its Value 的正确 XPATH 是什么。我假设我需要在 XPath 中过滤 data-id="987654321?

Answer 1

您的怀疑是正确的，您已经为完整路径指定了 XPath 查询，因此不需要循环。要在此示例中获取 "Newspaper" 和 "Fish" 节点，您可以简单地使用 SelectNodes 而不是循环和调用 SelectSingleNode。当然，如果有更多项可以遍历结果集，我在本例中通过索引访问它们，因为它们只有两个。

string sXPathT = "//span[contains(@class,'group-label')]";
string sXPathO = "//span[contains(@class,'group-value')]";

HtmlAgilityPack.HtmlDocument Doc = new HtmlDocument();
Doc.LoadHtml(strTestHTML);

var vOddL = Doc.DocumentNode.SelectNodes(sXPathT);
var vOddP = Doc.DocumentNode.SelectNodes(sXPathO);

string GroupLabelNewsPaper = vOddL.ElementAt(0).InnerText.Trim();
string GroupLabelFish = vOddL.ElementAt(1).InnerText.Trim();

string GroupValueNewspaper = vOddP.ElementAt(0).InnerText.Trim();
string GroupValueFish = vOddP.ElementAt(1).InnerText.Trim();

Console.WriteLine($"{GroupLabelNewsPaper}\t{GroupValueNewspaper}");
Console.WriteLine($"{GroupLabelFish}\t{GroupValueFish}");

输出：

Newspaper       82548828
Fish    8545852485

更新： 要获取特定的内容节点，您可以使用此 XPath：

string xpathForDataId = "//div[@class='content' and @data-id='987654321']";

你可以用上面的表达式过滤div，然后像这样得到它的子节点：

string sXPathT = ".//span[contains(@class,'group-label')]";
string sXPathO = ".//span[contains(@class,'group-value')]";
string xpathForDataId = "//div[@class='content' and @data-id='987654321']";

HtmlAgilityPack.HtmlDocument Doc = new HtmlDocument();
Doc.LoadHtml(strTestHTML);

var specificNode = Doc.DocumentNode.SelectSingleNode(xpathForDataId);

var vOddL = specificNode.SelectNodes(sXPathT);
var vOddP = specificNode.SelectNodes(sXPathO);

string GroupLabelBread = vOddL.ElementAt(0).InnerText.Trim();
string GroupLabelMilk = vOddL.ElementAt(1).InnerText.Trim();

string GroupValueBread = vOddP.ElementAt(0).InnerText.Trim();
string GroupValueMilk = vOddP.ElementAt(1).InnerText.Trim();

Console.WriteLine($"{GroupLabelBread}\t{GroupValueBread}");
Console.WriteLine($"{GroupLabelMilk}\t{GroupValueMilk}");

注意 sXPathT 和 sXPathO 中的“.//”。这样我们只搜索当前上下文而不是整个文档。

输出：

Bread   82548828
Milk    8545852485

HTML 解析 C# HTML 敏捷包

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