HTML - How do I know when all frames are loaded?

Question

I'm using .NET WebBrowser control. How do I know when a web page is fully loaded?

I want to know when the browser is not fetching any more data. (The moment when IE writes 'Done' in its status bar...).

Notes:

• The DocumentComplete/NavigateComplete events might occur multiple times for a web site containing multiple frames.
• The browser ready state doesn't solve the problem either.
• I have tried checking the number of frames in the frame collection and then count the number of times I get DocumentComplete event but this doesn't work either.
• this.WebBrowser.IsBusy doesn't work either. It is always 'false' when checking it in the Document Complete handler.

Answer 1

Here's how I solved the problem in my application:

private void wbPost_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
    if (e.Url != wbPost.Url)
        return;
    /* Document now loaded */
}

Answer 2

My approach to doing something when page is completely loaded (including frames) is something like this:

using System.Windows.Forms;
    protected delegate void Procedure();
    private void executeAfterLoadingComplete(Procedure doNext) {
        WebBrowserDocumentCompletedEventHandler handler = null;
        handler = delegate(object o, WebBrowserDocumentCompletedEventArgs e)
        {
            ie.DocumentCompleted -= handler;
            Timer timer = new Timer();
            EventHandler checker = delegate(object o1, EventArgs e1)
            {
                if (WebBrowserReadyState.Complete == ie.ReadyState)
                {
                    timer.Dispose();
                    doNext();
                }
            };
            timer.Tick += checker;
            timer.Interval = 200;
            timer.Start();
        };
        ie.DocumentCompleted += handler;
    }

From my other approaches I learned some "don't"-s:

• don't try to bend the spoon ... ;-)
• don't try to build elaborate construct using DocumentComplete, Frames, HtmlWindow.Load events. Your solution will be fragile if working at all.
• don't use System.Timers.Timer instead of Windows.Forms.Timer, strange errors will begin to occur in strange places if you do, due to timer running on different thread that the rest of your app.
• don't use just Timer without DocumentComplete because it may fire before your page even begins to load and will execute your code prematurely.