In C# how can i check if T is of type IInterface and cast to that if my object supports that interface?

Question

In C#, I have a function that passes in T using generics and I want to run a check to see if T is an object that implements a

Answer 1

The simplest form I can come up with is something like:

public IEnumerable GetRecords()
{
    IQueryable entities = new List().AsQueryable();

    if (typeof(IFilterable).IsAssignableFrom(typeof(T)))
    {
        entities = FilterMe(entities.OfType()).AsQueryable();
    }

    return entities;
}

public IEnumerable FilterMe(IEnumerable linked) where TSource : IFilterable
{
    return linked.Where(r => true).OfType();
}

The point here is the need to have types to pass into and get back out of the method. I had to change the types locally to get it working.

OfType will silently filter out items that are not really of a given type, so it assumes that it's a collection of the same type in any one call.

Because you are re-assigning from FilterMe, you still need the interface assignable check.