How to return value from Action()?

Question

In regards to the answer for this question Passing DataContext into Action(), how do I return a value from action(db)?

SimpleUsing.DoUsing(db => { 
// do whatever with db 
}); 

Should be more like:

MyType myType = SimpleUsing.DoUsing<MyType>(db => { 
// do whatever with db.  query buit using db returns MyType.
}); 

Answer 1

You can use Func<T, TResult> generic delegate. (See MSDN)

Func<MyType, ReturnType> func = (db) => { return new MyType(); }

Also there are useful generic delegates which considers a return value:

• Converter<TInput, TOutput> (MSDN)
• Predicate<TInput> - always return bool (MSDN)

---

Method:

public MyType SimpleUsing.DoUsing<MyType>(Func<TInput, MyType> myTypeFactory)

Generic delegate:

Func<InputArgumentType, MyType> createInstance = db => return new MyType();

Execute:

MyType myTypeInstance = SimpleUsing.DoUsing(
                            createInstance(new InputArgumentType()));

OR explicitly:

MyType myTypeInstance = SimpleUsing.DoUsing(db => return new MyType());