You can watch his keynote online here (Sarts at the 53:30 mark in the video).
He showed a number of fun demos during the keynote that highlighted some of new features coming in Silverlight 4. You can download the demos here (source code + VS project file included with each sample).
P.S. The Facebook application will also be available for download in the future.
And more here … Silverlight 4 demos from my PDC Keynote now available – ScottGu’s Blog
What Is The Difference Between an IoC Container and MEF?
MEF allows you to write your application as a series of much simpler mini applications, and have those brought together to create a much great whole
IoC container = service level components, MEF = Autonomous Components. A MEF "part" will probably use an IoC container
I recommend reading them highly, they will do a much better job than I could at explaining the detail of the decision points, Should I use MEF for my general IoC needs? and Should I use MEF with an IoC container?
Via What Is The Difference Between an IoC Container and MEF? – Jak Charlton – Insane World – Devlicio.us – Just the Tasty Bits
There is some obvious overlap but also a clear delineation. In particular when it comes to UI composition. MEF can be used for UI composition for sure, however it doesn’t have specific UI composition bits like RegionManager, Composite Commands, EventAggregator.
In general though here are the differences.
- First, MEF is in the platform as part of SL4/FX4.
- Second, MEF is a general UI agnostic composition technology while Prism is specific for UI composition. MEF also extends beyond composite applications to general extensibility / plugin models.
- Third, Prism and MEF can work together.
There are two primary use cases i hear about for MEF and Prism working together.
- Use Prism with MEF as an add-on for extensibility. That is make modules extensible through MEF. You can think of this as the “Two worlds in harmony” solution. Your core architecture rests on Prism’s modularity / and an IoC Container and sits side by side with MEF.
- Use MEF primarily for modularity, and pull in Prism bits for UI composition. In this model, your core architecutre sits on top of MEF, with MEF replacing the services of your IoC.
Via MEF and Prism, to be or not to be. – Glenn Block – CodeBetter.Com – Stuff you need to Code Better!
For SL 4 and .NET 4, the following assemblies are portable at the Siverlight surface area:
There are a great number of types and members in the .NET surface area that cannot run on Silverlight. As a result, you need to write code that targets the Silverlight versions of these assemblies in order to get this scenario to work.
Developers should write their portable logic in Silverlight Class Library projects, and then are free to reference such projects from both Silverlight and .NET application projects. To clarify, on the .NET side, you can reference such a library (Binary) from any kind of .NET project (Ex: WPF, winforms, WCF, WF, ASP.NET, …).
The following are the basic steps to follow to enable the use of portable code in Visual Studio 2010
- Setup projects
- Create .NET application
- Create or add existing Silverlight class library project
- Build Silverlight project
- Establish portable code reference
- Reference Silverlight class library binary from the .NET project
- Run App!
CLR Team Blog : Sharing Silverlight Assemblies with .NET Apps
An enhancement has been made that allows you to add animation when items are added ,or removed from, the list box. Silverlight 4 adds a new StateGroup to the ListBoxItem class:
A Simple Demo
The user types into the text box, clicks the add button and the text “floats” up into the list.
So Where Is the Magic??
To take advantage of the new FluidUI all you need to do is to set the behavior you want on any or all of the three new Visual States in the LayoutStates group of the ListBoxItem class.
The easiest way to do this is to open the project in Blend and right click on the ListBox. Choose Edit Additional Templates –> Edit Generated Item Container –> Edit a Copy
Name the new template and then click on the ListItem and open the States tab. For this simple demo, only modified the Loaded state.
To do so, click on the Loaded state and then expand the timeline. You’ll set new values for the entire Grid (which has 4 sub-elements).
select 0 seconds, and set the opacity to 0 and the y coordinate of a translate-transform to 200. Click save keyframe values, and then select 1 second and set the opacity to 1 and the y coordinate to 0. Save the new template…
Via Silverlight 4 Fluid UI – Jesse Liberty – Silverlight Geek