如何在C#中获取授权页面的HTML DOM内容

using System;
using System.Net.Http;
using System.Threading.Tasks;

class Program
{
    static async Task Main(string[] args)
    {
        string url = "授权页面的URL";

        using (HttpClient client = new HttpClient())
        {
            try
            {
                HttpResponseMessage response = await client.GetAsync(url);
                response.EnsureSuccessStatusCode();

                string htmlContent = await response.Content.ReadAsStringAsync();

                // 在这里对HTML内容进行解析和处理
                // ...

                Console.WriteLine(htmlContent);
            }
            catch (Exception ex)
            {
                Console.WriteLine("发生错误：" + ex.Message);
            }
        }
    }
}