In the March edition of MSDN Magazine, Charles Petzold writes an interesting article on Vector Graphics and the WPF Shape class. In this he describes several of the things to be mindful of when creating your own Shapes. Since Windows Presentation Foundation has Shapes

... elevated to a status nearly equal to to controls, often participating in layout and receiving mouse, keyboard and stylus input.

This means there are a number of things to take into account, such as the performance issues that might arise from allocating to much memory on the heap in some of the frequently used methods:

Because DefiningGeometry can be called at any time, and particularly whenever any property that affects the primitive changes, it's important to implement DefiningGeometry without routinely allocating memory from the heap. If every call to DefiningGeometry results in a heap allocation, eventually the Microsoft® .NET Framework garbage collector will need to take action. You should try to purge your DefiningGeometry code of any class instantiations, and you should also be aware of implicit heap allocations associated with some methods. Next I'll show you several techniques for avoiding heap allocations in your Shape derivatives.

In the article he supplies ample code-samples as well as the complete source of all the examples as a download. I especially like his ParallelPath shape!

This seems interesting:

Silvelight for Business Applications - Webcast

Silverlight gets high marks for its ability to deliver rich media, animation and graphics in cross-platform, cross-browser way. Did you know, however, that Silverlight is also a great platform for developing Rich Business Applications? Join us for a talk about how to use Silverlight for applications ranging from desktop-like line of business applications through to data visualization and BI. We’ll talk about the new features in Silverlight 2.0 that help business application developers, and discuss patterns and practices around their use. Learn how you can leverage your .NET skills to build browser-based rich business applications.

More WPF video tutorials from the Mix University. Since the last edition of Mix 3 days of WPF BootCamp 2008 have been added, providing you with plenty of new WPF video tutorials.

Spaghetti Code hosts a number of Webcasts and Podcasts concerning WPF, WCF and other .NET 3.5 related topics. One of the interesting ones is Shannon Brauns talk on real-world application development in WPF.

Shannon Braun, a Microsoft MVP, talks about enterprise WPF development in the real world. Shannon has been working for the past year on a large WPF project at a large customer here in the Twin Cities. During the podcast, we cover why WPF was used instead of WinForms, developer-designer integration, resources for getting started, and more. It's an informative 30 minutes and lays a good foundation for future podcasts around WPF.

Besides being an interesting talk, there are some lessons learned to be gained. Shannon discusses how they worked with a designer on the team and how WPF turned out to be an improvement (a slight one) and not a holy grail.

Yesterday I was reading the section 'Silvelight and Accessibility' in Adam Nathan's 'Silverlight 1.0 Unleashed'.It basically boils down to 'There is no Accessibility functionality in Silverlight'. Sure, there are a few options to provide 'Alt'-tags using:

function onLoad(plugin, userContext, sender)
{
var acc = plugin.content.accessibility;
acc.Title = "Crazy Clown Streetwear";
acc.Description = "This is a site about ... ";
acc.ActionDescription = "Click to find out more";

acc.addEventListener("PerformAction", "openRegularSite")
}

function penRegularSite(sender)
{
// Here you can add the code open the regular site
}

This will give screen readers on Windows only some information about your site as well as provide some default behaviour when a user clicks on the Silverlight plugin-part of the site. Read the MS documentation for more information on Accessibility

Luckily it seems this shortcoming of Silverlight will be fixed in version 2.0.Pete Brown blogs about some of the new features that will be in there. He also points out that there's a video in which Mark Rideout talks about the new features:

• Tabbing and tab order
• Focus and Keyboard Input
• Exposed Accessibility Tree (through UIA - UI Automation) for screen readers and other accessibility tools
• Accessibility Information directly in XAML Markup via
• AutomationProperties attached properties such as name and help text
• Support for AutomationPeer as in WPF
• Other capabilities such as notifications for high-contrast requirements

This all seems very promising. It will always be a challenge to make a visually oriented website with animations and all the other fancy layout-possibilities Silverlight offers screen-reader compatible. The new feature will help though.