April 2009 - Mike Taulty's Blog

Silverlight 3 has a new class called SystemColors and hanging off that class are a bunch of properties as below; If I write a Silverlight application today and draw a button on the screen as in; < Button Content ="Click Me" FontSize ="24" HorizontalAlignment ="Center" VerticalAlignment ="Center" /> then that displays as below; and you can see it running right next to Calculator. However…if I change my system colours in Windows to (e.g.) one of the high contrast settings; then this is what I end up with; that is – Calculator has played ball and so has FireFox but my Silverlight application isn’t really playing ball in that it has maintained its look and feel in spite of the system settings. It’d be nice if there was the possibility of the Silverlight application picking up those settings if the user/developer wants it to. Now, the SystemColors class is nice but it just has a bunch of static properties on it and nor is there any kind of change notification present when...

Just sharing a very small experiment I did with building a simple control that would use the new PlaneProjection capabilities in Silverlight 3 in order to present double-sided content which was capable of being flipped over. I did a similar thing in this FlickR project but I just wanted to make it a little more general (and I’d like to make it more general still if I get a chance to spend a little more time on it). I’ve shared the control project here for download – what this provides is a control called FlipControl which has properties; IsIdle FrontContent RearContent FlipAxis (Vertical/Horizontal) Duration OffsetX OffsetY OffsetZ and then a single method; Flip() and a single event; FlipCompleted and so I can go and use it in a Silverlight app with something like; < UserControl x:Class ="SilverlightApplication5.MainPage" xmlns ="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x ="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc ="clr-namespace:MikesControls;assembly...

I’m sure there’s a lot out there on this already but one of the things that I encountered in making this little application was the need to know when an image loaded from the network is actually ready to display in Silverlight. In that application, I have 2 images on the screen. What happens is something like this. Assume I have 2 images loaded in the app; OnTimerTick() Get the URL of the next image we’re going to display from FlickR Change the back image be displaying that new image by setting its URL. Run our “spin effect” animation to spin the back image to the front image. It’s something like that, anyway. Now, when I was first doing this I hit a problem. It wasn’t one that surprised me as I’ve seen it before and kind of expect it anyway. If I just do what I described then (because Silverlight loads the image from the URL asynchronously) I can get into a situation where I’m running my “spin effect” but the back image hasn’t yet loaded so I’m transitioning to a bunch of whited-out rectangles. That’s not good...

At the webdd on Saturday, a couple of people asked me about Silverlight 3 Out-Of-The-Browser applications ( or SLOOBs ) and questioned; Whether the actually work on the Mac What the experience is like for the user It occurred to me that this might be a reasonably common question for developers who are working on Windows and don’t have a Mac with OS X on it kicking around so that they can try these things out. SLOOBs do work fine on the Mac and I thought I’d make a short screencast where we build a simple SLOOB ( similar to the one that I used for demo purposes on Saturday ) and then deploy it to my iMac (running Leopard) and see what the Out-Of-The-Browser experience looks like over there. Here’s the video on Channel9 ( note – this is just a picture that jumps to the C9 page ); In discussing SLOOBs on the Mac we had a slightly more general discussion around whether there were any features that were Windows specific in Silverlight and I managed to come up with one or two e.g.; The Windowless parameter on the plug...

I was lucky enough to have a chance to chat with Aaron Skonnard at DevWeek last month and I captured a few videos which I thought I’d share here. Aaron (as you probably know) is a co-founder of the Pluralsight company and is a great trainer and technical presenter and was keynoting DevWeek with a talk about Cloud Computing so I manage to snag him and ask him a few questions about “the Cloud”. I’ve broken this down into a couple of sections, the first one here mostly being about timelines as we head towards Cloud; and then the second one here being more about how developers can prepare for Cloud computing; and then this last one here was really more of a “fun” question where I asked Aaron what he was currently playing with. I always find this an interesting question as I think all developers are always secretly toying with some bit of technology even if it means staying up late :-) Here’s Aaron’s answer; Enjoy!

Yesterday, by mistake, I tried to combine 2 features of Silverlight 3 that don’t work together. Unfortunately for me, it was in front of a bunch of people :-) I’d been briefly showing how you can decrease the size of a Silverlight 3 XAP by using the new project option in Visual Studio to reduce XAP size. The way this works is that; Microsoft assemblies that would usually be built into your XAP can be downloaded from microsoft.com This reduces the size of your XAP This benefits all applications as they don’t all end up packaging assemblies that are common So, generally, that’s all good stuff. However…it doesn’t work when you combine it with Out of the Browser applications – in the current beta when you take an application that’s using cached extensions out of the browser you’ll find that it doesn’t work ( for me, what happens is that the application doesn’t display anything when it’s taken out of the browser ). Now, I’d never actually meant to try and combine these 2 things in my demo – it was something that I...

Ian saw my post with a little Silverlight navigation application and dropped me a mail saying “couldn’t you make those URI’s a little more pretty with the UriMapper?” and he’s right :-) Tim has an explanation of UriMapper up here so I just followed that and mapped a few things and so now I should be able to use URI’s like these; http://www.mtaulty.com/downloads/SLMusic/music.html#artists http://www.mtaulty.com/downloads/SLMusic/music.html#albums http://www.mtaulty.com/downloads/SLMusic/music.html#albums?artist=Bob%20Dylan http://www.mtaulty.com/downloads/SLMusic/music.html#songs http://www.mtaulty.com/downloads/SLMusic/music.html#songs?artist=Bob%20Dylan http://www.mtaulty.com/downloads/SLMusic/music.html#songs?album=Blood%20On%20The%20Tracks not sure if I can do anything to pretty them up more than that but removing the need for the URI to contain “/Pages/{XYZ}.xaml” is definitely an improvement both from the point of view of convenience and of maintenance.

I’ve had a quick experiment with Silverlight 3 and navigation applications. There are some new classes in the assembly System.Windows.Controls.Navigation.dll – specifically one called a Frame and a base class to derive from called Page along with some helpers of which the most key appears to be NavigationSource. I built a little sample out of this. I wrote some .NET code that ran around my music library on my NAS and sucked out all the MP3 file information it could find and then I bundled that into an XML file and built a Silverlight app which shows that data. You can wander into the app by doing; http://mtaulty.com/downloads/SLMusic/music.html which is the same as visiting my artists page as in; http://mtaulty.com/downloads/SLMusic/music.html#/Pages/Artists.xaml but then there’s also my albums page which you can visit with; http://mtaulty.com/downloads/SLMusic/music.html#/Pages/Albums.xaml but you can also augment that query string as in; http://mtaulty.com/downloads/SLMusic/music.html#/Pages/Albums.xaml?artist...