HTMLAgilityPack的SelectNodes选择所有< IMG>分子 [英] HTMLAgilityPack SelectNodes to select all <img> elements

问题描述

我正在在C＃中的一个项目，基本上是一个图像搜索相关游戏的图像画面刮刀。我试图用HTMLAgilityPack选择所有图像元素，并把它们在HTMLNodeCollection，像这样的：

I am making a project in C# that's basically an image screen scraper for an image-search related game. I'm trying to use HTMLAgilityPack to select all the image elements and put them in an HTMLNodeCollection, like this:

//set up for checking autos

HtmlNodeCollection imgs = new HtmlNodeCollection(doc.DocumentNode.ParentNode);
imgs = doc.DocumentNode.SelectNodes("//img");

foreach (HtmlNode img in imgs)
{
    HtmlAttribute src = img.Attributes["@src"];
    urls.Add(src.Value);
}

注意网址的是一个公开名单集合：

Note that urls is a public List collection:

public List<string> urls = new List<string>();

我的f​​oreach循环抛出一个异常：

My foreach loop is throwing an exception:

对象引用未设置到对象的实例。

Object reference not set to an instance of an object.

检查汽车，果然，的 IMGS 的为空。有没有更好的办法可以追查这个问题的根源？我不知道，如果是我的XPath或内容。

Checking the autos, sure enough, imgs is null. Is there any better way I can track down the source of this problem? I have no idea if it's my Xpath or what.

最令人沮丧的是，我已经得到了它的工作，但搞砸了我的文件版本，失去了我的工作。 。DERP

The most frustrating part is that I had already gotten it to work, but messed up my file versions and lost my work. Derp.

推荐答案

您可能有以下行一个错字：

You might have a typo in the following line:

HtmlAttribute src = img.Attributes["@src"];

我得到这个工作对我来说（注意@位置）：

I got this to work for me (notice the @ position):

HtmlAttribute src = img.Attributes[@"src"];

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