Program.PublishSingleFile.cs

// Copyright © 2021 The CefSharp Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

using CefSharp.OffScreen;
using System;
using System.Diagnostics;
using System.IO;
using System.Threading;
using System.Threading.Tasks;

namespace CefSharp.MinimalExample.OffScreen
{
    /// <summary>
    /// For .Net 5.0/6.0/7.0 Publishing Single File exe requires using your own applications executable to
    /// act as the BrowserSubProcess. See https://github.com/cefsharp/CefSharp/issues/3407
    /// for further details. <see cref="Program.Main(string[])"/> for the default main application entry point
    /// </summary>
    public class ProgramPublishSingleFile
    {
        private static ChromiumWebBrowser browser;

        public static int Main(string[] args)
        {
            //Self Hosting the BrowserSucProcess
            var exitCode = CefSharp.BrowserSubprocess.SelfHost.Main(args);

            if (exitCode >= 0)
            {
                return exitCode;
            }

            const string testUrl = "https://www.google.com/";

            Console.WriteLine("This example application will load {0}, take a screenshot, and save it to your desktop.", testUrl);
            Console.WriteLine("You may see Chromium debugging output, please wait...");
            Console.WriteLine();

            var settings = new CefSettings()
            {
                //By default CefSharp will use an in-memory cache, you need to specify a Cache Folder to persist data
                CachePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "CefSharp\\Cache"),
                BrowserSubprocessPath = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName
            };

            //Perform dependency check to make sure all relevant resources are in our output directory.
            Cef.Initialize(settings, performDependencyCheck: false);

            // Create the offscreen Chromium browser.
            browser = new ChromiumWebBrowser(testUrl);

            // An event that is fired when the first page is finished loading.
            // This returns to us from another thread.
            browser.LoadingStateChanged += BrowserLoadingStateChanged;

            // We have to wait for something, otherwise the process will exit too soon.
            Console.ReadKey();

            // Clean up Chromium objects.  You need to call this in your application otherwise
            // you will get a crash when closing.
            Cef.Shutdown();

            return 0;
        }

        private static void BrowserLoadingStateChanged(object sender, LoadingStateChangedEventArgs e)
        {
            // Check to see if loading is complete - this event is called twice, one when loading starts
            // second time when it's finished
            // (rather than an iframe within the main frame).
            if (!e.IsLoading)
            {
                // Remove the load event handler, because we only want one snapshot of the initial page.
                browser.LoadingStateChanged -= BrowserLoadingStateChanged;

                var scriptTask = browser.EvaluateScriptAsync("document.querySelector('[name=q]').value = 'CefSharp Was Here!'");

                scriptTask.ContinueWith(t =>
                {
                    //Give the browser a little time to render
                    Thread.Sleep(500);
                    // Wait for the screenshot to be taken.
                    var task = browser.CaptureScreenshotAsync();
                    task.ContinueWith(x =>
                    {
                        // Make a file to save it to (e.g. C:\Users\jan\Desktop\CefSharp screenshot.png)
                        var screenshotPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "CefSharp screenshot.png");

                        Console.WriteLine();
                        Console.WriteLine("Screenshot ready. Saving to {0}", screenshotPath);

                        var bitmapAsByteArray = x.Result;

                        // Save the Bitmap to the path.
                        File.WriteAllBytes(screenshotPath, bitmapAsByteArray);

                        Console.WriteLine("Screenshot saved.  Launching your default image viewer...");

                        // Tell Windows to launch the saved image.
                        Process.Start(new ProcessStartInfo(screenshotPath)
                        {
                            // UseShellExecute is false by default on .NET Core.
                            UseShellExecute = true
                        });

                        Console.WriteLine("Image viewer launched.  Press any key to exit.");
                    }, TaskScheduler.Default);
                });
            }
        }
    }
}