C# WebBrowser control -- Get Document Elements After AJAX?

Question

I'm writing an application that uses the WebBrowser control to view web content that can change with AJAX that adds new content/elements. I can't seem to get at the new elements any way I've tried. BrowserCtl.DocumentText doesn't have the up-to-date page and of course it's not in "view source" either.

Is there some way to get this new data using this control? :( Please help. Thanks!

IE:

Browser.Navigate("www.somewebpagewithAJAX.com");
//Code that waits for browser to finish...
...
//WebBrowser control has loaded content and AJAX has loaded new content
// (is visible at runtime on form) but can't see them in Browser.Document.All
// or Browser.DocumentText :(

Answer 1

I solved the problem for me.

the key is, attaching a handler for onPropertyChanged event of the div element which is being populated via ajax call.

HtmlElement target = webBrowser.Document.GetElementById("div_populated_by_ajax");

if (target != null)
{
      target.AttachEventHandler("onpropertychange", handler);
}

and finally,

private void handler(Object sender, EventArgs e)
{
      HtmlElement div = webBrowser.Document.GetElementById("div_populated_by_ajax");
      if (div == null) return;
      String contentLoaded = div.InnerHtml; // get the content loaded via ajax
}

Answer 2

using System;
using System.Windows.Forms;

namespace WebBrowserDemo
{
    class Program
    {
        public const string TestUrl = "http://www.w3schools.com/Ajax/tryit_view.asp?filename=tryajax_first";

        [STAThread]
        static void Main(string[] args)
        {
            WebBrowser wb = new WebBrowser();
            wb.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(wb_DocumentCompleted);
            wb.Navigate(TestUrl);

            while (wb.ReadyState != WebBrowserReadyState.Complete)
            {
                Application.DoEvents();
            }

            Console.WriteLine("\nPress any key to continue...");
            Console.ReadKey(true);
        }

        static void wb_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            WebBrowser wb = (WebBrowser)sender;

            HtmlElement document = wb.Document.GetElementsByTagName("html")[0];
            HtmlElement button = wb.Document.GetElementsByTagName("button")[0];

            Console.WriteLine(document.OuterHtml + "\n");

            button.InvokeMember("Click");

            Console.WriteLine(document.OuterHtml);           
        }
    }
}

Answer 3

You will need to use DOM for it. Cast WebBrowser.Document.DomDocument to IHTMLDocument?. You will have to import some COM interfaces or Microsoft.mshtml assembly.

Have a look to http://msdn.microsoft.com/en-us/library/aa752641(VS.85).aspx for more details.