findicons国旗图标抓取爬虫C#版

FlagSpider.cs

using HtmlAgilityPack;
using RestSharp;
using System;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace FlagSpider
{
    class Program
    {   
        static void Main(string[] args)
        {
            int count = 0;
            string baseUrl = "https://findicons.com";

            for (int i = 1; i < 10; i++)
            {
                string url = $"{baseUrl}/pack/2838/flat_round_world_flag_icon_set/{i}";

                HtmlDocument htmlDoc = new HtmlDocument();
                htmlDoc.LoadHtml(GetContent(url));

                var query = from a in htmlDoc.DocumentNode.Descendants("a")
                            where a.GetAttributeValue("class", null) == "png_link downloadlink btn"
                            select a.Attributes["href"].Value;

                foreach (var item in query)
                {
                    Task.Factory.StartNew(async () =>
                    {
                        await Task.Delay(1500);
                        GetPic($"{baseUrl}{item}".Replace("128", "256"));
                        Console.WriteLine($"COUNT: {++count}");
                    });
                }
            }

            Console.ReadLine();
        }

        static string GetContent(string url)
        {
            RestClient client = new RestClient(url);
            RestRequest request = new RestRequest(Method.GET);
            request.AddHeader("cache-control", "no-cache");
            request.AddHeader("Connection", "keep-alive");
            request.AddHeader("accept-encoding", "gzip, deflate");
            request.AddHeader("Host", "findicons.com");
            request.AddHeader("Cache-Control", "no-cache");
            request.AddHeader("Accept", "*/*");
            request.AddHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 SE 2.X MetaSr 1.0");
            IRestResponse response = client.Execute(request);

            return response.Content;
        }

        static void GetPic(string url)
        {
            string fileName = $"{url.Split("/")[6]}.png";

            Console.WriteLine($"Start download {fileName} ...");

            RestClient client = new RestClient(url);
            RestRequest request = new RestRequest(Method.GET);
            byte[] response = client.DownloadData(request);

            File.WriteAllBytes(Path.Combine(Directory.GetCurrentDirectory(), "flags" ,fileName) , response);

            Console.WriteLine($"Download {fileName} success.");
        }
    }
}