Get current WebBrowser DOM as HTML

Question

I want to use the HTML ability pack on a WebBrowser that has loaded all the things I need (It clicks a button with code to load every video on the channel) (It loads a YouTu

Answer 1

If the target website uses AJAX heavily (as Youtube does), it's hard, if not impossible, to determine when the page has finished loading and executing all dynamic scripts. But you could get close by handling window.onload event and allowing an extra second or two for non-deterministic AJAX calls. Then call webBrowser.Document.DomDocument.documentElement.outerHTML via dynamic to get the currently rendered HTML.

Example:

private void Form1_Load(object sender, EventArgs e)
{
    DownloadAsync("http://www.example.com").ContinueWith(
        (task) => MessageBox.Show(task.Result),
        TaskScheduler.FromCurrentSynchronizationContext());
}

async Task<string> DownloadAsync(string url)
{
    TaskCompletionSource<bool> onloadTcs = new TaskCompletionSource<bool>();
    WebBrowserDocumentCompletedEventHandler handler = null;

    handler = delegate
    {
        this.webBrowser.DocumentCompleted -= handler;

        // attach to subscribe to DOM onload event
        this.webBrowser.Document.Window.AttachEventHandler("onload", delegate
        {
            // each navigation has its own TaskCompletionSource
            if (onloadTcs.Task.IsCompleted)
                return; // this should not be happening
            // signal the completion of the page loading
            onloadTcs.SetResult(true);
        });
    };

    // register DocumentCompleted handler
    this.webBrowser.DocumentCompleted += handler;

    // Navigate to url
    this.webBrowser.Navigate(url);

    // continue upon onload
    await onloadTcs.Task;

    // artificial delay for AJAX
    await Task.Delay(1000);

    // the document has been fully loaded, can access DOM here
    return ((dynamic)this.webBrowser.Document.DomDocument).documentElement.outerHTML;
}

[EDITED] Here's the final piece of code that helped to solve the OP's problem:

HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(((dynamic)this.webBrowser1.Document.DomDocument).documentElement.ou‌​terHTML);