Tag Archives: silverlight

A Silverlight UI for Windows Mobile 7, backward compatibility in doubt

Note: speculative post; I have no official information on this.

It’s been rumoured for ages; but at this point I would be surprised if the Windows Mobile 7 UI were not built with Silverlight. Consider:

  • Silverlight has to be supported – it should have been in 6.5 – otherwise nobody will take mobile Silverlight seriously
  • WM7 has to have excellent UI design; and WPF/Silverlight is Microsoft’s designer-friendly UI framework
  • Silverlight 4 already supports touch control in the current beta
  • Scaling/Zooming is baked into Silverlight and ideal for a mobile UI
  • If Silverlight is present on the device it would make sense to build the UI with it

If this is right, there are a couple of interesting aspects for developers. It will make Silverlight a more attractive platform in scenarios such as Enterprise roll-outs where the device can be specified.

The awkward question: what about all those existing Windows Mobile apps built either with native code or with the compact framework? Again, there are rumours of lack of backward compatibility. Does that mean that all Windows Mobile 7 apps with a UI will have to be done in Silverlight? That’s what John Biggs says:

WinMo 7 will not run 6.x code. End of story. It is based on Silverlight and .Net. Everything save a few basic programs will not work under WinMo 7. There is no expectation that this will be a “business device” and the focus is currently on games including some XBox Live functionality for gaming and messaging. There will be a Microsoft App store with an easy approval process.

I find this a stretch. I can believe that Microsoft might initially target the consumer market, or have crippled “consumer” versions; but not that it would give up on mobile business apps – we heard at PDC (to the point of tedium) how Microsoft is supporting “three screens and a cloud”, unified for developers by Visual Studio. There’s no reason why Silverlight should not be used for business apps.

What about backward compatibility though? Traditionally Microsoft does a good job of keeping your old stuff running, within reason; possibly too good – Windows is full of compatibility hacks that may be to its detriment overall.

Another point to bear in mind: WM7 needs a browser, and I don’t see Microsoft re-implementing IE in Silverlight.

So I’m sceptical about this too; but with Windows Mobile at such a low ebb could the company decide it has little to lose?

Silverlight 4 with COM can do anything – on Windows

At PDC Microsoft played down the significance of adding COM support to Silverlight 4 when run out of the browser and fully trusted (you can also be out of the browser and not fully trusted). The demos were of Office automation, and journalists were told that the feature was there to satisfy the requests of a few Enterprise customers.

Now former Microsoft Silverlight program manager Justin Angel, who has implemented his blog in Silverlight, has spelt out what we all knew, that Silverlight with COM support can do just about anything. His richly-illustrated blog post has code examples for:

  • reading and writing to any file (subject I guess to the permissions of the current user)
  • executing any command or file
  • emulating user input with WShell.SendKeys
  • pinning files to the Windows 7 taskbar
  • reading any registry values
  • adding an application to the Windows startup folder
  • doing text to speech using Windows built-in engine
  • accessing local databases with ODBC
  • automating scanners and cameras
  • using the Windows 7 location API, accessing the full .NET Framework
  • and of course … automating Microsoft Office.

Well, fully trusted means fully trusted; and these are great features for powerful though Windows-only Silverlight applications, though I hope no user installs and trusts one of these applets thinking it is “only Silverlight” and can’t do much harm.

The post also has comments on the lack of any equivalent feature for the Mac in Silverlight 4:       

If Microsoft chooses to not go ahead with Mac support in Silverlight 4 RTM, well, it’s not because they couldn’t

says Angel, suggesting that it would be easy to add AppleScript support. (I had to type that quote – no clipboard support in Silverlight 3).

Of course there is time for Microsoft to unveil such a feature, say at Mix10 in March, though I wouldn’t count on it.