Using C# 3 (.NET 3.5) for ASCX and ASPX files in SharePoint 2010

Question

In an OOTB SharePoint 2010 Server installation, if you use C# 3 in your code-in-front, it doesn't compile, since the C# 2 compiler is used to compile the markup. (At least for me - SharePoint 2010 Server on Windows 7).

So how do you enable the use of C# 3 and .NET 3.5 for ASCX and ASPX files in SharePoint 2010? If I use var or extension methods, my web parts and page layouts won't compile.

Answer 1

Won't compile?? Are you referring to Visual Studio Error OR Runtime Error?

SharePoint 2010 is based on .net 3.5 and it will work fine.

if it's Visual Studio change the project framework to 3.5

Answer 2

SharePoint 2010, despite being "built on .NET 3.5", requires modifications to the web.config of any Web Application that should compile controls and layouts using .NET 3.5.

These modifications can either be applied directly to the web.config file of the Web Application, or one of the two SharePoint methods for web.config modifications can be used:

• Using the copyappbincontent stsadm command, in combination with a web.config merge file
• Using the SPWebConfigModification classes