Question

Just curious if anyone has had sufficient time with WinRT yet to understand whether there are areas in WinRT and .NET 4.5 that efface to the .NET programmer some of the old items encountered in VSTO and COM Interop Office programming pertaining to RCWs and the differences in the COM reference counting and .NET GC beyond not using finalizer (making sure you get a reference to all .NET RCWs, etc).

Not a big deal just curious if they abstracted away those considerations or better yet the architecture is materially different and these concerns are not even applicable.

Thanks in advance

Maybe a better way of asking the question is whether it still is materially the same architecture of .NET Objects in a managed/garbage collected memory model referencing COM (WinRT) objects in an unmanaged (yet sandboxed) reference counting memory architecture?

Unless there is some “magic” in the meta data bindings or the sandboxed environment, then we will just need to apply the same approach we had with RCWs.

Answer 1

I’ve built two complete apps on the developer preview in C#/XAML. The WinRT objects feel just like regular C# objects. No need for finalizers or other traditional .NET/COM interop stuff. The projections to .NET make the WinRT API pretty seamless.

There are some areas where COM leaks through.

• Exceptions thrown by WinRT objects have no stack trace
• The majority of the exceptions thrown by WinRT objects have a generic exception type and include an HRESULT error code.

I expect these issues will get resolved in future builds of Windows 8.

There are also some redundancies now where similar types are defined in both WinRT and .NET (IObservableVector and INotifyCollectionChanged)