C# .NET 3.0/3.5 features in 2.0 using Visual Studio 2008

Question

What are some of the new features that can be used in .NET 2.0 that are specific to C# 3.0/3.5 after upgrading to Visual Studio 2008? Also, what are some of the features that aren't available?

Available

• Lambdas
• Extension methods (by declaring an empty System.Runtime.CompilerServices.ExtensionAttribute)
• Automatic properties
• Object initializers
• Collection Initializers
• LINQ to Objects (by implementing IEnumerable extension methods, see LinqBridge)

Not Available

• Expression trees
• WPF/Silverlight Libraries

Answer 1

You can use any new C# 3.0 feature that is handled by the compiler by emitting 2.0-compatible IL and doesn't reference any of the new 3.5 assemblies:

• Lambdas (used as Func<..>, not Expression<Func<..>> )
• Extension methods (by declaring an empty System.Runtime.CompilerServices.ExtensionAttribute)
• Automatic properties
• Object Initializers
• Collection Initializers
• LINQ to Objects (by implementing IEnumerable<T> extension methods, see LinqBridge)