Re: ListView - Caching Thumbnails?


"nak" <a@xxxxx> wrote in message news:3B5A014D-6C62-4403-8BB4-4DC8852E5912@xxxxxxxxxxxxxxxx
Hi Dale

That was my thought too. I'm in the midst of some restructuring right now though (see my other question on looking for an XML tutorial for details), so I may put the extension back in. It isn't really *crucial* that the user doesn't change the files. The program just will yield some odd results if they do (which I figure they can deal with if they are monkeying with the database ;).

Here's one I wrote a while back, a little dated now as it was written for .net 1.0, but it should still work,

http://www.npsoftware.co.uk/Tutorials/tut_data_persistence_XML.php

Personally I don't use databases unless I really need to, I think they are overused and not everyone wants SQL Server installed, even if it is an Express edition. Access databases fill the middle ground I guess but still, you can edit XML by hand.

I'm throwing around the term 'database' a bit too liberally here. Basically I'm building up a collection of XML files, and image files (JPGs), that will be stored in a data directory. I tend to stay away from more 'formal' databases as well (unless I have a really strong call for it). I've been working with Chris's example (dunawayc), and having a lot of success with it. Only problem, is I have to do a lot of backend restructuring, but in the end I think its worth it.


Basically they are images that the user imports in to an internal database. The underlying goal here is to create an interactive anatomical atlas program using high resolution images. Basically, it is a tool to help students learn/study anatomy. The user (or the prof) brings in an image, tags it with certain attributes (i.e. this is x,y,z). The images then become 'clickable' and will bring up a description of what ever you clicked on. The description is then also clickable, and contains links to related topics, and images within the database (this is where the thumbnails come in... in the search box, the user is presented with thumbnails of the 'hits').

Aaah okay, then there is allot to think about in that respect, as I'm not entirely how your app will be setup. Like how is the application going to be accessed? Client based instancing or a Web Browser? What data exactly is going to be shared?

I'm going 'old school' on it. I despise webbased apps for this kind of thing. The images are too big to deliver efficiently (the ones I'm working at the moment with total more than 10GB...), so most people end of scaling the images down. Trying to learn, this can be *really* frustrating, as you'll be looking at the file, and you just want to zoom in 'a little bit' but you're stuck, and you know the original image was higher resolution, but they cut it back to make the CD/DVD etc.

You also then have to worry a lot more about security/access rights if the database is shared between users.

So, yeah, the whole thing is going to be released on a DVD, and the user can do what the heck they like with it. I've pretty well decided now that if the user messes with the back end stuff, then it serves them right if the program crashes on them. (they'll just have to delete the files they changed to get it to work again.).

Decisions eh? lol! Good luck anyway!

Lots of fun. Luckily I have the next 3 months to get it all working as I want it to. Then I go back to school (and next year's class gets to play with my program and find all the bugs in it ;) ).

Dale

.

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