Is there any way to write a WinRt (Metro) app that will also work on Windows 7 and Vista?

Question

We can’t just leave our customers that are not able to upgrade to windows 8 for a long time in the larch. However there is demand for a “tablet”/”touch” versio

Answer 1

As others have noted, you would not want to have exactly the same application working in Win8 Metro and Win7 / Vista Desktop. If you structure your application properly, using a suitabel design pattern, it is possible to share quite a bit of code between the various version that you would require. For the Win8 version, you will be using WinRT, for Win7 / Vista you have a choice of Silverlight or WPF.

I have published a couple of articles that demonsrate how this can be done, they include quite a bit of code as well:

• XAMLFinance – A Cross-platform WPF, Silverlight & WP7 Application - while this article does not cover Win8, it does share code from WPF to Windows Phone 7, which is a very similar problem.
• TweetSearch – A Cross platform Metro UI WinRT and Silverlight Application - this article shows how to use the same techniques to share code between WinRT and Silverlight