what is the C# compiler option for specifying the version of .net framework

Question

I have look completely in this two msdn article C# Compiler Options Listed Alphabetically and C# Compiler Options Listed by Category for compiler option for specifying the target framework version which can be used in command line building. I got to know that we can specify the framework version in app.config with supportedRuntime element.

Can we use this element( configuration > startup > supportedRuntime ) in web.config also(in case of asp.net application) ?

I have not needed to do it with only command line switch. I just asking this question only because of curious to know about it.

Answer 1

The compiler doesn't care about what version of the framework , only the version of the runtime and the language .

The cl.exe program just compiles and links whatever you throw at it, and it is up to you to add references to .NET 4.5-specific assemblies or not. You can choose to reference older versions of external references by specifically asking for a version using a fully qualified assembly name.

The setting in Visual Studio is just a filter that shows/hides assemblies when you are adding references.