linq - Consuming anonymous type in an Expression

Question

The Entity Framework has a function with this signature:

public EntityTypeConfiguration<TEntityType> HasKey<TKey>(Expression<Func<TEntityType, TKey>> keyExpression);

If your table has a clustered primary key you can represent that like this:

this.HasKey(t => new { t.Field1, t.Field2 });

My question is, how are they consuming this anonymous type? I would like to build some similar functionality in methods of my own, that allow a lambda expression that returns multiple properties.

Is there some special way to peek into an anonymous type?

Answer 1

They just use reflection.

For additional performance, you can use expression trees to store pre-compiled delegates in a generic type.