C# HtmlAgilityPack 并选择节点和子节点
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HtmlAgilityPack and selecting Nodes and Subnodes
提问by The Hyman
Hope somebody can help me.
希望有人可以帮助我。
Let′s say I have a html document that contains multiple divs like this example:
假设我有一个包含多个 div 的 html 文档，如下例所示：
<div class="search_hit">
<span prop="name">Richard Winchester</span>
<span prop="company">Kodak</span>
<span prop="street">Arlington Road 1</span>
</div>
<div class="search_hit">
<span prop="name">Ted Mosby</span>
<span prop="company">HP</span>
<span prop="street">Arlington Road 2</span>
</div>
I′m using HtmlAgilityPack to get the html document. What i need to know is how can i get the spans for each "search_hit"-div?
我正在使用 HtmlAgilityPack 来获取 html 文档。我需要知道的是如何获得每个“search_hit”-div 的跨度？
My first thought was something like this:
我的第一个想法是这样的：
foreach (HtmlAgilityPack.HtmlNode node in doc.DocumentNode.SelectNodes("//div[@class='search_hit']"))
{
foreach (HtmlAgilityPack.HtmlNode node2 in node.SelectNodes("//span[@prop]"))
{
}
}
Each div should be a object with the included spans as properties. I. e.
每个 div 应该是一个包含跨度作为属性的对象。IE。
public class Record
{
public string Name { get; set; }
public string company { get; set; }
public string street { get; set; }
}
And this List shall be filled then:
然后应填写此列表：
public List<Record> Results = new List<Record>();
But the XPATH i′m using is not doing a search in the subnode as it should do. It seams that it searches the whole document again and again.
但是我使用的 XPATH 并没有像它应该做的那样在子节点中进行搜索。它接缝一次又一次地搜索整个文档。
I mean I already got it working in that way that i just get the the spans of the whole page. But then i have no relation between the spans and divs. Means: I don′t know anymore which span is related to which div.
我的意思是我已经让它以这种方式工作，我只是得到了整个页面的跨度。但是我在跨度和 div 之间没有关系。意思是：我不知道哪个跨度与哪个 div 相关。
Does somebody know a solution? I already played around that much that i′m totally confused now :)
有人知道解决方案吗？我已经玩了那么多，我现在完全糊涂了:)
Any help is appreciated!
任何帮助表示赞赏！
采纳答案by shriek
The following works for me. The important bit is just as BeniBela noted to add a dot in second call to 'SelectNodes'.
以下对我有用。重要的一点正如 BeniBela 指出的那样，在第二次调用“SelectNodes”时添加一个点。
List<Record> lstRecords=new List<Record>();
foreach (HtmlNode node in doc.DocumentNode.SelectNodes("//div[@class='search_hit']"))
{
Record record=new Record();
foreach (HtmlNode node2 in node.SelectNodes(".//span[@prop]"))
{
string attributeValue = node2.GetAttributeValue("prop", "");
if (attributeValue == "name")
{
record.Name = node2.InnerText;
}
else if (attributeValue == "company")
{
record.company = node2.InnerText;
}
else if (attributeValue == "street")
{
record.street = node2.InnerText;
}
}
lstRecords.Add(record);
}
回答by BeniBela
If you use //, it searches from the document begin.
如果使用//，它将从文档开始搜索。
Use .//to search all from the current node
用于.//从当前节点搜索所有
foreach (HtmlAgilityPack.HtmlNode node2 in node.SelectNodes(".//span[@prop]"))
Or drop the prefix entirely to search just for direct children:
或者完全删除前缀以仅搜索直接子项：
foreach (HtmlAgilityPack.HtmlNode node2 in node.SelectNodes("span[@prop]"))
回答by Oscar Mederos
First of all, take a look at this: Html Agility Pack - Problem selecting subnode
首先看看这个：Html Agility Pack - Problem selection subnode
Here is a full working solution for your question:
这是您问题的完整工作解决方案：
IList<Record> results = new List<Record>();
foreach (var node in doc.DocumentNode.SelectNodes("//div[@class='search_hit']")) {
var record = new Record();
record.Name = node.SelectSingleNode(".//span[@prop='name']").InnerText;
record.company = node.SelectSingleNode(".//span[@prop='company']").InnerText;
record.street = node.SelectSingleNode(".//span[@prop='street']").InnerText;
results.Add(record);
}
If you read the question I pointed you to, you will see that doing ./span[@prop='name']is exactly the same, since those spannodes are (direct) children of the divnode.
如果您阅读了我向您指出的问题，您会发现这样做./span[@prop='name']是完全相同的，因为这些span节点是该div节点的（直接）子节点。
If the spannodes do not have those propattributes, and you want to assign them depending on the order they appear, you can do:
如果span节点没有这些prop属性，并且您想根据它们出现的顺序分配它们，您可以执行以下操作：
foreach (var node in doc.DocumentNode.SelectNodes("//div[@class='search_hit']")) {
var spanNodes = node.SelectNodes("./span");
var record = new Record();
record.Name = spanNodes[0].InnerText;
record.company = spanNodes[1].InnerText;
record.street = spanNodes[2].InnerText;
results.Add(record);
}
回答by The Hyman
Shame on me :)
为我感到羞耻:)
All of you were right.
你们都是对的。
I found the problem. This NullReferenceException kept nagging me so I spent more time to look at it in detail. In between all those divs there was one div with the same "class='search-hit'" attribute but without the spans inside. Thats why it throughs an error at the second loop.
我发现了问题。这个 NullReferenceException 一直困扰着我，所以我花了更多的时间来详细研究它。在所有这些 div 之间，有一个 div 具有相同的“class='search-hit'”属性，但内部没有跨度。这就是为什么它在第二个循环中出现错误的原因。
foreach (HtmlAgilityPack.HtmlNode node in doc.DocumentNode.SelectNodes("//span[@prop]/ancestor::div[@class='search_hit']"))
{
Record rec = new Record();
foreach (HtmlAgilityPack.HtmlNode node2 in node.SelectNodes(".//span[@prop]"))
{
}
rList.Results.Add(rec);
}
The code above is working.
上面的代码正在工作。
Thank you guys for your time and help!
谢谢你们的时间和帮助！
回答by ibrahim ozboluk
I used that. class convert id
我用过那个。类转换id
HtmlNodeCollection nodes = dokuman.DocumentNode.SelectNodes("//div[@id='search_hit']//span[@prop]");
for (int i = 0; i < nodes .Count; i++)
{
var record = new Record();
record.Name = links[i].InnerText; results.Add(record); }
