MIX07 - Developing Silverlight Applications with JavaScript

I just emerged from a standing-room-only demonstration of how to work with Silverlight and JavaScript. It seems that the managed code way of working with Silverlight is a 1.1 thing that’s coming soon (before Summer 07? I’d have to see the slides again); if you want to write a Silverlight application today, you’ll be using JavaScript.

It looks like working in Silverlight with XAML with JavaScript is a lot like working with the HTML DOM in JavaScript. You get elements, you manipulate properties, you respond to events… and it’s just as hard to debug as your standard client-side JavaScript app. The demos were interesting, showing how you do different things like start animations, intercept mouse events… but they were far from bug-free. I guess that’s just one of the pain points for early adoption.

Beyond that pain point, though, it looks pretty good. No harder than doing stuff you’re probably already doing, but with a much richer end result.

Two of the key things shown were the Downloader and the CreateFromXAML call.

The Downloader is a component that allows you to synchronously or asynchronously download content. It will also report on the status of the progress as it goes, so you can have an actual progress bar. This looks useful if you’ve got some large content like a lot of video where you want to download some to cache before starting the video playing. The Downloader supports ZIP, too, so if you have some compressed content to download, you’re set to go.

The CreateFromXAML method is sort of like an “eval” call - it takes some XAML that you’ve built up in code and parses it into native XAML nodes that can be inserted into your application. This is handy for building XAML content programmatically - say, adding rows to a table.

I like what I’ve seen so far from Silverlight, but I’ve yet to get some hands-on. I think my next stop is the lab area where you can get some first-hand experience with it by going through some walkthroughs and such.