WebBrowser Events

[arpan_de]

At the top of almost all the pages in VBForums.com, there are links for internet.com. When the mouse is hovered over some of these links like IT, Developer, News etc., a drop-down menu pops-up.

When I open a VBForums page in a browser which I have created using the WebBrowser control & hover the mouse over any of these links, the drop-down menu pops-up....that's fine but strangely the DownloadBegin & DownloadComplete events of the WebBrowser control also fire each time the mouse is moved over such links!

Now why are these 2 events firing when the mouse is moved over such links?

As it is, on most occasions, the DocumentComplete event fires more than once; that's the reason I thought of making use of the DownloadComplete event but this event behaves insanely!

[Doogle]

I've been playing with WebBrowser as a result of another thread, you may find it interesting: http://www.vbforums.com/showthread.php?t=504545 as far as the DocumentComplete event is concerned. As to the DownLoadBegin and Complete activity, I don't see that happening.

[arpan_de]

You mean you don't see the DownloadBegin & DownloadComplete events firing more than once? If yes, have you tried navigating to this forum using the WebBrowser control?

If a web page loads very fast (like www.google.com), then these 2 events fire only once but if a web page takes some time to download, then these 2 events fire multiple times.

[Doogle]

No, I don't see those events triggering when I hover the mouse over the Internet.com menu items.

When navigating to the home page of this site using http://www.vbforums.com/ two http requests are actually generated so there will be two DownLoadBegin and DownLoadComplete events. (Plus 2 of most of the other events associated with navigation)

The code I posted in the thread referenced earlier uses the WebBrowser control to demonstrate - perhaps you could try it and see.

[arpan_de]

You are very much correct that it makes 2 HTPPP requests but how did you come to the conclusion that it sends 2 HTTP requests?

[Doogle]

Past experience with writing 'screen-scraping' applications and having long nights wondering why sometimes the DocumentComplete event seemed to trigger to early. I still haven't found a 100% reliable method of determining when the Document requested is loaded properly.

Using in-line Error Handling is probably the easiest circumvention, check if an Error of "Object Variable with Block Variable Not Set" is returned, if it is then go round a loop until it isn't, if there isn't an error then you know the Document is ready.

Whenever I start out on these types of Applications I usually go through the process of 'debug.print'ing the output from the Navigation events for the particular pages I'm interested in (as per that code I posted in the other thread) so I have a reasonable idea of what I'm up against.