问题
I have following configuration of my PC:
- Windows 8
- Visual Studio 2012
- .NET Framework 4.5
My Project Configuration is:
- WP 7.1
- Silverlight 4.0
- .NET Framework 4.0
- CTP ASYNC (installed, using async and await keywords)
The project was written using VS2010 on Windows 7 machine for WP7.1. Now I have upgraded the PC to Windows 8 and have installed VS2012.
The project, however, complaining about 'async' modifier.
Cannot find all types required by the 'async' modifier. Are you targeting the wrong framework version, or missing a reference to an assembly?
Any idea how to solve this problem?
thank you!
回答1:
There is a newer version of the Async targeting package which supports Silverlight 4. Search for Microsoft.BCL.Async in NuGet, or run install-package Microsoft.Bcl.Async –prein the Package Manager Console. The package supports SL4, WP 7.1+ and Portable Libraries (yes!)
You will find a detailed description in the BCL team's blog Using async/await without .NET Framework 4.5
回答2:
From the page you downloaded from:
This targeting pack is not required for projects targeting .NET Framework 4.5 or .NET for Windows Store apps. It is only required for projects targeting Silverlight 5 and .NET Framework 4.0. Earlier platform releases are not supported.
Upgarde to Silverlight 5?
来源：https://stackoverflow.com/questions/13974610/error-cannot-find-all-types-required-by-the-async-modifier-are-you-targeting