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CDP

.NET bindings for the Chrome DevTools Protocol

Documentation about the protocol can be found at the following:

Protocols

Usage

using System;
using System.IO;
using CDP;
using CDP.Protocols;

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        // "using" clause ensures that close the chrome process
        using (chrome) {
            chrome.Page.FrameNavigated += (sender, e) => {
                Console.WriteLine("FrameNavigated: " + e.Frame.Id);
            };
            chrome.Start();
            chrome.Page.Enable();
            chrome.Page.Navigate("http://google.com");
            var png = chrome.Page.CaptureScreenshot();
            File.WriteAllBytes("Screenshot.png", png.Data);
            chrome.Delay(1000);
        }
    }
}

Enable event receiver

use chrome.[Domain].Enable() to enable receiving events.

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();
            chrome.Runtime.ConsoleAPICalled += (sender, e) => {
                Console.WriteLine("ConsoleAPICalled: {0}", e);
            };
            chrome.Runtime.Enable();

            chrome.Page.DomContentEventFired += (sender, e) => {
                Console.WriteLine("DomContentEventFired: {0}", e.Timestamp);
            };
            chrome.Page.Enable();

            chrome.Page.SetDocumentContent(
                chrome.FrameId,
                @"<html>
                <head>
                <script>
                console.log('console.log test');
                </script>
                </head>
                <body>
                </body>
                </html>"
            );
            chrome.Delay(1000);
        }
    }
}

Open new tab

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();

            TargetJson target = chrome.OpenNewTab("http://google.com");
            HeadlessChrome chrome2 = chrome.Open(target);

            // use chrome2 to control the new tab
        }
    }
}

Protocol version

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();

            // library version
            Console.WriteLine(HeadlessChrome.Version);

            // browser version
            Console.WriteLine(chrome.GetVersion());
        }
    }
}

Update the protocol version of the library

  • Download the source code for this repository
  • Execute the following code
using CDP;

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();
            ProtocolJson protocol = chrome.GetProtocol();
            string outputPath = "Protocols";
            ProtocolBuilder.Build(protocol, outputPath);
        }
    }
}
  • Overwrite "Protocols" folder created in the executable file folder to the source code
  • Rebuild library

Send a request manually

using CDP;

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();

            // the return value is a JSON string
            string result = chrome.Send("Browser.close");
            Console.WriteLine(result);
        }
    }
}

Send a request manually with parameters

using CDP;

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();

            // use an anonymous class when specifying parameters
            string result = chrome.Send(
                "Page.setDocumentContent",
                new {
                    frameId = chrome.FrameId,
                    html = "<html><body>Test</body></html>"
                }
            );
            Console.WriteLine(result);
        }
    }
}

Send a request manually (asynchronous)

  • Asynchronous methods call in APM manner
  • Tasks and async/await are not yet supported
using CDP;

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();

            AsyncCallback callback = (IAsyncResult asyncResult) => {
                // the return value is a JSON string
                string result = chrome.EndSend(asyncResult);
                Console.WriteLine(result);
            };
            chrome.BeginSend(
                "Browser.close", callback, null
            );
            chrome.Delay(1000);
        }
    }
}

Set timeout

using CDP;

class MainClass {
    public static void Main(string[] args) {
        HeadlessChrome chrome = new HeadlessChrome(
            HeadlessChrome.DefaultAppPathMac
        );
        using (chrome) {
            chrome.Start();

            // specify the timeout value in milliseconds
            chrome.SendTimeout = 1000;

            // enable throwing exceptions when sending
            // if not enabled, null is returned
            chrome.ThrowExceptionOnSend = true;
            chrome.Page.Crash();
            chrome.Delay(2000);
        }
    }
}

Updated