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C#使用PuppeteerSharp库的示例代码

作者:rjcql

PuppeteerSharp 是一个用于在 .NET 平台上控制无头(Headless) Chrome 浏览器的库,本文主要为大家详细介绍了C#中使用PuppeteerSharp库的工具类,需要的可以了解下

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

        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

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

到此这篇关于C#使用PuppeteerSharp库的示例代码的文章就介绍到这了,更多相关C# PuppeteerSharp内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!

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