Question

I need to convert an object to a generic collection, look:

var currentEntityProperties = currentEntity.GetType().GetProperties();

foreach (var currentEntityProperty in currentEntityProperties)
{
    if (currentEntityProperty.PropertyType.GetInterfaces().Any(
                x => x.IsGenericType &&
                x.GetGenericTypeDefinition() == typeof(ICollection<>)))
    {
        var collectionType = currentEntityProperty.PropertyType.GetInterfaces().Where(
                                x => x.IsGenericType &&
                                x.GetGenericTypeDefinition() == typeof(ICollection<>)).First();

        var argumentType = collectionType.GetGenericArguments()[0];

        // now i need to convert the currentEntityProperty into a collection, something like that (this is wrong, so, what is thr right way?):
        var currentCollection = (ICollection<argumentType.GetType()>)currentEntityProperty.GetValue(currentEntity, null);
    }
}

How can i do this?

Obs: i need with this collection call the except method with another collection (this collection i get with the same way of the currentCollection, with a anotherEntityProperty.GetValue(anotherEntity, null))

var itens = currentCollection.Except(anotherCollection);

Answer 1

Dynamic typing lets you make the compiler and DLR do all the work here:

dynamic currentCollection = ...;
dynamic anotherCollection = ...;
dynamic items = Enumerable.Except(currentCollection, anotherCollection);

At execution time, that will do all the reflection work for you and pick the most appropriate type argument.