The type or namespace name 'Caching' does not exist in the namespace 'System.Runtime'

问题

I know there is usually a simple solution to this which is reference the dll in add references. But I have added the reference and system.runtime.caching appears in my references list but the error still displays.

The error displays in the browser in runtime so it does compile.

I have removed and re added the reference but still no luck. I have restarted VS 2012 and restarted.

Visual Studio 2012 .net framework 4.5

Screen shot:

回答1:

I had the same issue, and I found out that I manually had to add:

<assemblies>
  <add assembly="System.Runtime.Caching, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
</assemblies>

to my web.config file.

回答2:

The most likely cause of this error is that you are using a Client Profile version of the .Net framework.

回答3:

I had a similar issue and it went away when I changed the target framework of the from .NET Framework 4 Client Profile to .Net Framework 4

来源：https://stackoverflow.com/questions/14200018/the-type-or-namespace-name-caching-does-not-exist-in-the-namespace-system-run