Html Agility Pack の使用方法

導入

Html Agility Pack を NuGet からインストールする。

実装方法

void Main()
{
	WebScrapingRunner.RunAsync().Wait();
}

public static class WebScrapingRunner
{
	public static async Task RunAsync()
	{
		// 時間計測用のタイマー
		var timer = new System.Diagnostics.Stopwatch();
		timer.Start();
		
		using (var client = new HttpClient() { Timeout = TimeSpan.FromMilliseconds(30000) })
		{
			var targetUri = new Uri("https://www.gotokyo.org/eventlist/ja/list");
			var pageHtml = await client.GetHtmlAsync(targetUri);
			Console.WriteLine(pageHtml.DocumentNode.WriteTo());
		}

		Console.WriteLine("HTML取得完了: {0:0.000}秒", timer.Elapsed.TotalSeconds);
	}
}

public static class HttpClientExtensions
{
	public static async Task<HtmlDocument> GetHtmlAsync(this HttpClient httpClient, Uri requestUri)
	{
		var response = await httpClient.GetAsync(requestUri);
		return await response.Content.ReadAsHtmlAsync();
	}

	public static async Task<HtmlDocument> ReadAsHtmlAsync(this HttpContent httpContent)
	{
		var html = await httpContent.ReadAsStringAsync();
		var doc = new HtmlDocument();
		doc.LoadHtml(html);
		return doc;
	}
}