// Copyright 2014 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 System;
using System.Diagnostics;
using System.IO;
using System.Threading.Tasks;
using CefSharp.DevTools.Page;
namespace CefSharp.OffScreen.Example
{
public class Program
{
private const string TestUrlOne = "https://www.google.com/";
private const string TestUrlTwo = "https://github.com/";
private const string TestUrlThree = "https://www.google.com/doodles";
private const string TestUrlFour = "https://microsoft.com/";
public static int Main(string[] args)
{
Console.WriteLine("This example application will load {0}, take a screenshot, and save it to your desktop.", TestUrlOne);
Console.WriteLine("You may see a lot of Chromium debugging output, please wait...");
Console.WriteLine();
//Console app doesn't have a message loop which we need as Cef.Initialize/Cef.Shutdown must be called on the same
//thread. We use a super simple SynchronizationContext implementation from
//https://devblogs.microsoft.com/pfxteam/await-synchronizationcontext-and-console-apps/
//Continuations will happen on the main thread
//The Nito.AsyncEx.Context Nuget package has a more advanced implementation
//https://github.com/StephenCleary/AsyncEx/blob/8a73d0467d40ca41f9f9cf827c7a35702243abb8/doc/AsyncContext.md#console-example-using-asynccontext
AsyncContext.Run(async delegate
{
Cef.EnableWaitForBrowsersToClose();
var settings = new CefSettings();
//The location where cache data will be stored on disk. If empty an in-memory cache will be used for some features and a temporary disk cache for others.
//HTML5 databases such as localStorage will only persist across sessions if a cache path is specified.
settings.CachePath = Path.GetFullPath("cache");
var success = await Cef.InitializeAsync(settings);
if (!success)
{
return;
}
var t1 = MainAsync(TestUrlOne, TestUrlTwo, "cache\\path1", 1.0);
//Demo showing Zoom Level of 2.0
//Using seperate request contexts allows the urls from the same domain to have independent zoom levels
//otherwise they would be the same - default behaviour of Chromium
var t2 = MainAsync(TestUrlThree, TestUrlFour, "cache\\path2", 2.0);
await Task.WhenAll(t1, t2);
Console.WriteLine("Image viewer launched. Press any key to exit.");
// Wait for user input
Console.ReadKey();
//Wait until the browser has finished closing (which by default happens on a different thread).
//Cef.EnableWaitForBrowsersToClose(); must be called before Cef.Initialize to enable this feature
//See https://github.com/cefsharp/CefSharp/issues/3047 for details
Cef.WaitForBrowsersToClose();
// Clean up Chromium objects. You need to call this in your application otherwise
// you will get a crash when closing.
Cef.Shutdown();
});
//Success
return 0;
}
private static async Task MainAsync(string url, string secondUrl, string cachePath, double zoomLevel)
{
var browserSettings = new BrowserSettings
{
//Reduce rendering speed to one frame per second so it's easier to take screen shots
WindowlessFrameRate = 1
};
var requestContextSettings = new RequestContextSettings
{
CachePath = Path.GetFullPath(cachePath)
};
// RequestContext can be shared between browser instances and allows for custom settings
// e.g. CachePath
using (var requestContext = new RequestContext(requestContextSettings))
using (var browser = new ChromiumWebBrowser(url, browserSettings, requestContext))
{
if (zoomLevel > 1)
{
browser.FrameLoadStart += (s, argsi) =>
{
var b = (ChromiumWebBrowser)s;
if (argsi.Frame.IsMain)
{
b.SetZoomLevel(zoomLevel);
}
};
}
await browser.WaitForInitialLoadAsync();
//Check preferences on the CEF UI Thread
await Cef.UIThreadTaskFactory.StartNew(delegate
{
var preferences = requestContext.GetAllPreferences(true);
//Check do not track status
var doNotTrack = (bool)preferences["enable_do_not_track"];
Debug.WriteLine("DoNotTrack: " + doNotTrack);
});
var onUi = Cef.CurrentlyOnThread(CefThreadIds.TID_UI);
// For Google.com pre-pupulate the search text box
if (url.Contains("google.com"))
{
await browser.EvaluateScriptAsync("document.querySelector('[name=q]').value = 'CefSharp Was Here!'");
}
//Example using SendKeyEvent for input instead of javascript
//var browserHost = browser.GetBrowserHost();
//var inputString = "CefSharp Was Here!";
//foreach(var c in inputString)
//{
// browserHost.SendKeyEvent(new KeyEvent { WindowsKeyCode = c, Type = KeyEventType.Char });
//}
////Give the browser a little time to finish drawing our SendKeyEvent input
//await Task.Delay(100);
var contentSize = await browser.GetContentSizeAsync();
var viewport = new Viewport
{
Height = contentSize.Height,
Width = contentSize.Width,
Scale = 1.0
};
// Wait for the screenshot to be taken,
// if one exists ignore it, wait for a new one to make sure we have the most up to date
var bitmap = await browser.CaptureScreenshotAsync(viewport:viewport);
// 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" + DateTime.Now.Ticks + ".png");
Console.WriteLine();
Console.WriteLine("Screenshot ready. Saving to {0}", screenshotPath);
File.WriteAllBytes(screenshotPath, bitmap);
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
});
await browser.LoadUrlAsync(secondUrl);
// Gets a warpper around the CefBrowserHost instance
// You can perform a lot of low level browser operations using this interface
var cefbrowserHost = browser.GetBrowserHost();
//You can call Invalidate to redraw/refresh the image
cefbrowserHost.Invalidate(PaintElementType.View);
contentSize = await browser.GetContentSizeAsync();
viewport = new Viewport
{
Height = contentSize.Height,
Width = contentSize.Width,
Scale = 1.0
};
// Wait for the screenshot to be taken,
// if one exists ignore it, wait for a new one to make sure we have the most up to date
bitmap = await browser.CaptureScreenshotAsync(viewport: viewport);
screenshotPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "CefSharp screenshot" + DateTime.Now.Ticks + ".png");
Console.WriteLine();
Console.WriteLine("Screenshot ready. Saving to {0}", screenshotPath);
File.WriteAllBytes(screenshotPath, bitmap);
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
});
}
}
}
}