C# WebBrowser, injecting JavaScript doesn't update HtmlDocument

Question

I'm trying to resolve an issue that's disconcerting me. It might be something obvious but I can't really figure out what's wrong.

I have a winform with a WebBrowser which I load this way and it works fine:

    WebBrowser.DocumentText = someHtmlCode;

In my winform's webbrowser I can right-click to get the HTML source and check out that the code is the same I set in the DocumentText property... everything's ok at this point.

So once I get it loaded and working, I inject some JavaScript code into it, something like this:

    HtmlElement head = WebBrowser.Document.GetElementsByTagName("head")[0];
    HtmlElement scriptEl = WebBrowser.Document.CreateElement("script");
    IHTMLScriptElement element = (IHTMLScriptElement)scriptEl.DomElement;
    element.text = "function sayHello() { alert('hello') }";
    head.AppendChild(scriptEl);

So I'm adding a new JavaScript function named "sayHello" that I can call this way, and it's still working properly:

    WebBrowser.Document.InvokeScript("sayHello");

So everything's ok at this point, I can run the JavaScript function and getting the alert inside the WebBrowser, but what's disconcerting me is that when I right-click on the WebBrowser to get the source code, I get the same code I set at the beginning. No trace about the JavaScript code added later, although it's there because it's working when I invoke it.

Of course, if I look into the WebBrowser.HtmlDocument, I can't see the JavaScript either, it's the same that I get looking at the source code.

So my question is: where's the new JavaScript code going and how can I get it back? I need to get the updated HTML code.

Thanks!

Answer 1

Source Code does not give you updated document. To get updated document you have to use following

HtmlElement head = WebBrowser.Document.GetElementsByTagName("head")[0];
string h = head.innerHtml;

The only option is to navigate top node and get innerHtml for current state of Html.