.NET 利用PuppeteerSharp生成页面图片

安装 NuGet 程序包 - PuppeteerSharp

Install-Package PuppeteerSharp

创建个控制台程序。

新方法

class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            CreateHtmlImg();

            Console.ReadLine();
        }
        static async void CreateHtmlImg()
        {
            //  首次 执行程序 会先下载一个 chrome 程序 ， 下载完成后下次就不用下载。
            await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);

            using (Browser browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true }))
            {
                using (var page = await browser.NewPageAsync())
                {
                    //设置浏览器的页面大小
                    await page.SetViewportAsync(new ViewPortOptions
                    {
                        Width = 1024,
                        Height = 768
                    });
                    string url = "https://www.cnblogs.com/";
                    await page.GoToAsync(url);

                    // 可执行javasctipt
                    //var seven = await page.EvaluateFunctionAsync<int>("()=> 4 + 3");
                    //var someObject = await page.EvaluateFunctionAsync<dynamic>("(value) => ({a: value})", 5);


                    var html = await page.GetContentAsync();

                    var sourceFile = "";
                    var memoryStream = new MemoryStream(Encoding.Default.GetBytes(html));
                    var sr = new StreamReader(memoryStream);
                    sourceFile = sr.ReadToEnd();

                    //针对源代码进行分析
                    sr.Close();

                    //将页面保存为图片
                    using (var stream = await page.ScreenshotStreamAsync(new ScreenshotOptions { FullPage = false }))
                    {

                        byte[] srcBuf = new Byte[stream.Length];
                        stream.Read(srcBuf, 0, srcBuf.Length);
                        stream.Seek(0, SeekOrigin.Begin);
                        using (FileStream fs = new FileStream(@"D:垃圾"+ DateTime.Now.ToString("yyyyMMddHHmmsssss") +".png",FileMode.Create, FileAccess.Write))
                        {
                            fs.Write(srcBuf, 0, srcBuf.Length);
                        }
                    }
                    //将页面保存为图片
                    //await page.ScreenshotAsync(@"D:垃圾"+ DateTime.Now.ToString("yyyyMMddHHmmsssss") +".png",
                    //new ScreenshotOptions() { FullPage = true, Type = ScreenshotType.Png };
                }
            }
        }
    }

首次执行会比较慢，要下载 Chrome ，330M