匿名类型无法符合接口或从任何东西派生.

Lambdas和delegates提供函数作为变量.

Object Expressions的文档声明了这一点,这使它听起来像语言方便.

You use object expressions when you want to avoid the extra code and
overhead that is required to create a new,named type. If you use
object expressions to minimize the number of types created in a
program,you can reduce the number of lines of code and prevent the
unnecessary proliferation of types. Instead of creating many types
just to handle specific situations,you can use an object expression
that customizes an existing type or provides an appropriate
implementation of an interface for the specific case at hand.

你可以用这样的东西伪造它(虽然你不能将它限制在一个接口)

var foo = new { square = new Func<int,int>(x => x * x) };