Program.cs

using MasterDevs.ChromeDevTools.Protocol.Chrome.Page;
using System;
using System.IO;
using System.Linq;
using System.Threading;
using MasterDevs.ChromeDevTools.Protocol.Chrome.DOM;
using Task = System.Threading.Tasks.Task;

namespace MasterDevs.ChromeDevTools.Sample
{
 internal class Program
 {
 const int ViewPortWidth = 1440;
 const int ViewPortHeight = 900;
 private static void Main(string[] args)
 {
 Task.Run(async () =>
 {
 // synchronization
 var screenshotDone = new ManualResetEventSlim();

 // STEP 1 - Run Chrome
 var chromeProcessFactory = new ChromeProcessFactory(new StubbornDirectoryCleaner());
 using (var chromeProcess = chromeProcessFactory.Create(9222, true))
 {
 // STEP 2 - Create a debugging session
 var sessionInfo = (await chromeProcess.GetSessionInfo()).LastOrDefault();
 var chromeSessionFactory = new ChromeSessionFactory();
 var chromeSession = chromeSessionFactory.Create(sessionInfo.WebSocketDebuggerUrl);

 // STEP 3 - Send a command
 //
 // Here we are sending a commands to tell chrome to set the viewport size 
 // and navigate to the specified URL
 await chromeSession.SendAsync(new SetDeviceMetricsOverrideCommand
 {
 Width = ViewPortWidth,
 Height = ViewPortHeight,
 Scale = 1
 });

 var navigateResponse = await chromeSession.SendAsync(new NavigateCommand
 {
 Url = "http://www.google.com"
 });
 Console.WriteLine("NavigateResponse: " + navigateResponse.Id);

 // STEP 4 - Register for events (in this case, "Page" domain events)
 // send an command to tell chrome to send us all Page events
 // but we only subscribe to certain events in this session
 var pageEnableResult = await chromeSession.SendAsync<Protocol.Chrome.Page.EnableCommand>();
 Console.WriteLine("PageEnable: " + pageEnableResult.Id);

 chromeSession.Subscribe<LoadEventFiredEvent>(loadEventFired =>
 {
 // we cannot block in event handler, hence the task
 Task.Run(async () =>
 {
 Console.WriteLine("LoadEventFiredEvent: " + loadEventFired.Timestamp);

 var documentNodeId = (await chromeSession.SendAsync(new GetDocumentCommand())).Result.Root.NodeId;
 var bodyNodeId =
 (await chromeSession.SendAsync(new QuerySelectorCommand
 {
 NodeId = documentNodeId,
 Selector = "body"
 })).Result.NodeId;
 var height = (await chromeSession.SendAsync(new GetBoxModelCommand {NodeId = bodyNodeId})).Result.Model.Height;

 await chromeSession.SendAsync(new SetDeviceMetricsOverrideCommand
 {
 Width = ViewPortWidth,
 Height = height,
 Scale = 1
 });

 Console.WriteLine("Taking screenshot");
 var screenshot = await chromeSession.SendAsync(new CaptureScreenshotCommand {Format = "png"});

 var data = Convert.FromBase64String(screenshot.Result.Data);
 File.WriteAllBytes("output.png", data);
 Console.WriteLine("Screenshot stored");

 // tell the main thread we are done
 screenshotDone.Set();
 });
 });

 // wait for screenshoting thread to (start and) finish
 screenshotDone.Wait();

 Console.WriteLine("Exiting ..");
 }
 }).Wait();
 }
 }
}