The Full Story on Developing for Media Center in Windows Vista

 2006年1月5日，在Media center sandbox blog上有这样一篇文章：

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Finally the day has come for me to outline the full story on the the designer / developer platform in Media Center for Windows Vista. Do you remember when I asked What Platform Features Do You Want for Media Center in Windows Vista? One of the comments on that post from Michael Schoneman resonated clearly with our thinking and seemed to sum up much of the feedback we have heard over the last few years...

“We want SDK support for the cool graphic effects you guys have.  I really love the way stuff slides and zooms on and off the screen.  I want to be able to build something that looks like it's a part of the system, not something bolted onto the side.”

We have listened. Media Center for Windows Vista will expose three ways from which you can choose to deliver full featured software and experiences to your customers.

• Windows Media Center Presentation Layer Applications
• Hosted Microsoft .NET Framework 3.0 XAML Browser Applications (XBAP)
• Hosted HTML Applications

Paradigm #1: Windows Media Center Presentation Layer Application
Media Center Add Ins were first available in the 2004 version of Media Center as managed code assemblies which could fully leverage the Microsoft .NET Framework, access the full Media Center application programming interface (API) and run on-demand or as a background process. The Media Center Application Programming Interfaces (API) allow granular control of Media Center audio / video playback, interoperability with the digital video recording (DVR) features of Media Center and parental controls as well as full access to the Microsoft .NET Framework platform for developing applications which are easier to build, manage, deploy, and integrate with other networked systems.

However, Media Center Add Ins were limited to a single user interface mechanism: a Media Center styled dialog box. While useful for some tasks (such as system wide notifications) Media Center Adds Ins in prior versions were limiting to full-featured application development due to their inability to project a more meaningful user interface.

Media Center in Windows Vista greatly expands and enhances the user interface capabilities of Media Center Add Ins allowing for the creation of full fidelity experiences on par with or exceeding Media Center itself using the new Windows Media Center Presentation Layer via Media Center Markup Language and the Microsoft .NET Framework 2.0. To fully differentiate from prior versions we are calling these new experiences Windows Media Center Presentation Layer Applications.

Windows Media Center Presentation Layer Applications now have access to the same rendering technologies the eHome team uses to produce Media Center itself with the Windows Media Center Presentation Layer.  The Windows Media Center Presentation Layer provides dynamic layout capabilities, integrated animation support, rich text and graphic support, automatic keyboard / remote navigation and more via Media Center Markup Language.

To top it all off, experiences created as Windows Media Center Presentation Layer Applications will remote with full fidelity to the XBox 360 Media Center Extender. That means your experiences will look just as good on the XBox 360 as they do on the Media Center PC itself.

Media Center Markup Language (MCML) is an XML based declarative language that instructs the Windows Media Center renderer in how to display a user interface within the Windows Media Center Presentation Layer. MCML supports advanced concepts such as parameterization, private local storage, rich conditional based data binding and composition-based animated visual content and access to managed code assemblies from markup. Authoring in MCML is an exercise in producing a view description and supplying it with data via managed code interfaces in the managed code Model.

Which brings me to yet another comment conversation Chris Anderson and I had over on his post First Take: XBox 360 Media Center Extender. Chris wrapped things up nicely with the following...

"One last thought. If you think about it, the conventional way of navigating a CD music collection is via the text on the "spine" or edge of the CD, not its cover, just as in a book collection. So perhaps that would be the way to do it. Show the album covers if you want, but underneath it also show the spine view. But of course the broad point is that more display options are better; as you point out, one size doesn't fit all."

It's worth pointing out a third party can create this EXACT view using the new Windows Media Center Presentation Layer -- and it can look and perform just as nicely as the built-in Media Center features. I think Chris will be pleased if the market agrees with him and creates his uber-perfect view of his digital library.

Paradigm #2: Hosted Microsoft .NET Framework 3.0 XAML Browser Applications (XBAP)
We introduced the ability to use XBAP applications in Media Center at PDC 2005. The Microsoft .NET Framework 3.0 is the next generation platform for Windows allowing you to develop for both traditional mouse / keyboard Windows desktop experiences and remote controlled experiences using common tools and shared / reusable resources. The Microsoft .NET Framework 3.0 team has provided great tools for designers in Microsoft Expression Graphic Designer (aka 'Acrylic') and Microsoft Expression Interactive Designer (aka 'Sparkle'). To learn more about using the Microsoft .NET Framework 3.0 in Windows Media Center view the Professional Developers Conference 2005 presentation.

Paradigm #3: Hosted HTML Applications
Existing applications written in HTML will continue to work and be supported in Media Center for Windows Vista with zero or few modifications needed by the third party. Long term we hope folks will move to either Windows Media Center Presentation Layer Applications or Microsoft .NET Framework 3.0 XBAPs because the experiences can be so much more immersive and rich, but we will maintain compatability for Hosted HTML since it is so ubiquitous.

Questions, Comments...?
We have posted the Windows Media Center Software Development Kit (SDK) to the Windows Vista beta program and made it available to MSDN Subscribers along with the December CTP. We are inviting any and all folks who have access to these resources to take a look at the new SDK and tell us what you think by...

• Filing a bug report as part of the Windows Vista beta.
• Leaving a comment on this post.
• Sending email directly to one of us.

Aaron and I will be sharing more details in the coming weeks and months.

So, what do you think? Have we given you what you wanted?

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