C# 使用PuppeteerSharp工具类

写在前面

类库介绍：PuppeteerSharp 是一个用于在 .NET 平台上控制无头（Headless） Chrome 浏览器的库。它允许开发者通过编程方式模拟浏览器行为，执行网页操作，截取网页截图，获取网页内容，可以把网页转换成PDF等等。PuppeteerSharp 是 Puppeteer 在 .NET 环境中的等效实现，Puppeteer 是由 Google 提供的一个用于控制无界面浏览器 Chrome 的工具。

老规矩通过NuGet进行安装

代码实现

cs 复制代码

        public static async void DoScreenshot(string url)
        {
            using var browserFetcher = new BrowserFetcher();
            await browserFetcher.DownloadAsync();
            await using var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true });
            await using var page = await browser.NewPageAsync();
            await page.SetViewportAsync(new ViewPortOptions
            {
                Width = 1920,
                Height = 1080
            });
            await page.GoToAsync(url);
            var picPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "test.jpg");
            await page.ScreenshotAsync(picPath);
            await browser.CloseAsync();
        }

        public static async void ExportAsPdf(string url)
        { 
            using var browserFetcher = new BrowserFetcher();
            await browserFetcher.DownloadAsync();
            await using var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true });
            await using var page = await browser.NewPageAsync();
            await page.GoToAsync(url);
            //等待字体加载完毕
            await page.EvaluateExpressionHandleAsync("document.fonts.ready");
            var pdfPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "test.pdf");
            await page.PdfAsync(pdfPath);
            await browser.CloseAsync();
        }

        public static async void FetchUrls(string url)
        {
            //浏览器配置
            var options = new LaunchOptions { Headless = true };
            await new BrowserFetcher().DownloadAsync();

            //打开浏览器
            using (var browser = await Puppeteer.LaunchAsync(options))
            using (var page = await browser.NewPageAsync())
            {
                //加载页面
                await page.GoToAsync(url);
                var urlList = new List<string>();
                //获取所有超链接
                var jsSelectAllAnchors = @"Array.from(document.querySelectorAll('a')).map(a => a.href);";
                var urls = await page.EvaluateExpressionAsync<string[]>(jsSelectAllAnchors);
                foreach (string u in urls)
                {
                    urlList.Add($"Url: {u}");
                }
                var urlPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "urls.txt");
                File.WriteAllLines(urlPath, urlList);
                await browser.CloseAsync();
            }
        }


        public static async void SearchTest(string url)
        {
            using var browserFetcher = new BrowserFetcher();
            await browserFetcher.DownloadAsync();
            await using var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true });
            await using var page = await browser.NewPageAsync();
            await page.SetViewportAsync(new ViewPortOptions
            {
                Width = 1920,
                Height = 1080,
                //Devtools = true // 启用 Chrome DevTools,无头配置将自动禁用
            });

            //load: window.onload事件被触发时候完成导航,某些情况下它根本不会发生。
            //domcontentloaded: Domcontentloaded事件触发时候认为导航成功
            //networkidle0: 在 500ms 内没有网络连接时就算成功(全部的request结束),才认为导航结束
            //networkidle2: 500ms 内有不超过 2 个网络连接时就算成功(还有两个以下的request),就认为导航完成
            //加载时长 networkidle0 > networkidle2 > load > domcontentloaded 
            //await page.GoToAsync(url, new NavigationOptions() { WaitUntil = new WaitUntilNavigation[] { WaitUntilNavigation.Networkidle0 } });

            // 跟踪日志
            //await page.Tracing.StartAsync(new TracingOptions { Path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory,"race.json") });
            //await page.Tracing.StopAsync();

            await page.GoToAsync(url);
            await page.WaitForSelectorAsync(".searchbox input");
            await page.FocusAsync(".searchbox input"); // 聚焦
            await page.Keyboard.TypeAsync("CN Tower, Toronto, Ontario, Canada"); // 键盘输入
            await page.ClickAsync(".searchIcon"); // 点击
            await page.WaitForNavigationAsync();
            var content = await page.GetContentAsync();

            // 下载配置
            //var cdp = await page.Target.CreateCDPSessionAsync();
            //await cdp.SendAsync("Page.setDownloadBehavior", new
            //{
            //    behavior = "allow",
            //    downloadPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "testing_downloads")
            //});
            //await cdp.DetachAsync();
        }

调用示例

cs 复制代码

PuppeteerHelper.DoScreenshot("https://www.baidu.com/");
PuppeteerHelper.ExportAsPdf("https://www.baidu.com/");
PuppeteerHelper.FetchUrls("https://www.baidu.com/");

执行结果如下：

需要注意的是运行时记得科学上网，不然还是手动将chrome包下载好后，下载后内容是这样的

官网源码： https://github.com/hardkoded/puppeteer-sharp