WinRT and WPF in Windows 8

Question

As I understand, WinRT is a different version of WPF written without using the underlying Win32 APIs.

What's the relation of WinRT and WPF? Will WPF work under Metro in Windows 7 or will it launch the classic desktop?

That's not so clear from the Keynote. If someone has Windows 8 installed can confirm it's behaviour.

Thanks

Answer 1

WinRT is a replacement for the Winapi. The api is native, very unlike WPF that runs as a layer on top of the CLR. It certainly resembles WPF, part of what causes confusion. It adopted the metadata format of managed code, replacing type libraries of old. And uses XAML for UI designs, much like WPF, Silverlight and Windows Phone. You can still write WPF apps for Windows 8 but your app can't be published through the store, won't integrate with the Metro desktop nor will it run on tablets that are based on the ARM core. Whether that's a real problem depends a great deal on how well Metro will do in the market place.

Answer 2

There is no relation between WPF and WinRT, just like there is no relation between Silverlight and WPF. Now we have three technologies, WPF, Silverlight and WinRT.

If you try to execute WPF application, it will not execute on Metro, it will execute in the classical desktop only.

In Visual Studio 2011, you have WPF and Metro as two different types of applications, and Xaml for WPF and WinRT is not same, Xaml for WinRT is pretty much same as that of Silverlight as lot of classes which exist for WPF are missing in WinRT library. But most of classes that exist for Silverlight are available in WinRT.