从URL加载html的两种方法?

现在看来 User-Agent 标题是必需的 your site .

HtmlAgilityPack 但你应该改变 DownloadString(url) 方法。如果您使用 Fiddler ,您将看到它返回 403 Forbidden :

解决方案是添加任何 用户代理 请求的标题:

using HtmlAgilityPack;
using System;
using System.Net;

class Program
{
    static void Main()
    {
        var doc = DownloadSource("https://videohive.net/item/inspired-slideshow/21544630");
        Console.ReadKey();
    }

    public static HtmlDocument DownloadSource(string url)
    {
        try
        {
            HtmlDocument doc = new HtmlDocument();
            doc.LoadHtml(DownloadString(url));
            return doc;
        }
        catch (Exception e)
        {
            // exception handling here
        }
        return null;
    }

    static String DownloadString(String url)
    {
        WebClient client = new WebClient();
        client.Headers.Add("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:x.x.x) Gecko/20041107 Firefox/x.x");
        return client.DownloadString(url);
    }
}