问题
I was looking to see if the Async CTP with a portable class library?
回答1:
No. The Async CTP has different dlls for Desktop, Phone, Silverlight 4, and Silverlight 5.
Hopefully in the near future, all these platforms will support Task (and async) natively, and then portable class libraries would be able to use async.
Update: Microsoft.Bcl.Async can be installed for portable libraries targeting .NET 4.0/4.5, Windows Store apps, Silverlight 4/5, and Windows Phone 7.5/8.0
回答2:
As a heads up, we've started planning a release of Async that will support down-level (.NET 4.0, SL5, Phone 7.5) portable:
http://visualstudio.uservoice.com/forums/121579-visual-studio/suggestions/2691068-support-async-in-portable-class-libraries
回答3:
In Visual Studio 2012 RTM async/await syntax can be used in Portable Class Libraries, at least when targeting .NET 4.5 and WinRT.
Edit: It's now possible to use async/await even in Portable Class Libraries targeting WP7.5/WP8 + Silverlight 4/5 + .NET 4.0/4.5 + WinRT using Microsoft.Bcl.Async library.
回答4:
You can use beta version of Microsoft.Bcl.Async - I already use it in my projects and it behaves stable to be used in real projects.
来源：https://stackoverflow.com/questions/9152634/can-the-async-ctp-be-used-with-a-portable-library