Question

Let’s say I have two Tables, Lunch and Dinner. I know that both contain the DateTime property “Time”.

If I have a generic method GetTime, how could I return db.Lunch.Time when T is Lunch and db.Dinner.Time when T is Dinner? I’m trying to achieve this without testing for T individually using typeof, but rather generically.

Pseudocode:

public T GetTime<T>(DateTime dt)
{
    return MyDataContext.GetTable<T>().Where(entity => entity.Time == dt);
}

So when I call GetTime<Dinner> it will automatically look in the Dinner Table for all dinner entities with the property time equal to my supplied parameter dt.

The problem is that I can’t specifiy entity.Time in my expression because T is a generic. My question is how to get around that, so that I can look for any T (knowing that all my entities in fact have the Time property) without having to create specific methods for Dinner and Lunch.

Answer 1

You’d have to have both classes implement an interface something like this:

public interface IMyInterface
{
   DateTime Time{get;set;}
}

And then in your generic method:

public void MyMethod<T>(T item) where T: IMyInterface
{
    //here you can access item.Time
}