How do I iterate a generic reflected method?

Question

In my CMS I have a load of modules which allow me to do some clever item listing stuff. I am trying to use them to pull out a list of their child objects via reflection, but am getting stuck with the level of generics involved.

I have got as far as this method:

var myList = moduleObj.GetType().GetMethod("ChildItems").Invoke(moduleObj, new object[] { });

which returns a List. Each modulespecificobject is bound it an IItemListable interface which has the methods in it I am trying to access.

I am unsure how I can cast or iterate the myList object as a set of IItemListable objects access the methods required.

Thanks

A few of the classes:

public interface IItemListable
{
    IQueryable GetQueryableList();
    string GetIDAsString();
    IItemListable GetItemFromUrl(string url, List<IItemListable> additionalItems);
    bool IsNewItem();
    IItemListable CreateItem<T>(ItemListerControl<T> parentList) where T : class, IItemListable;
    IItemListable LoadItem(string id);
    IItemListable SaveItem();
    RssToolkit.Rss.RssItem ToRssItem();
    void DeleteItem();
    string ItemUrl();
}

public interface IItemListModule<T> where T: IItemListable
{
    List<T> ChildItems();
}


public class ArticlesModule : ItemListModuleBase<Article>, IItemListModule<Article>
{
    #region IItemListModule<Article> Members

    public new List<Article> ChildItems()
    {
        return base.ChildItems().Cast<Article>().Where(a => a.IsLive).ToList();
    }

    #endregion
}

Answer 1

Maybe this will help:

http://devlicio.us/blogs/louhaskett/archive/2007/06/13/how-to-cast-between-list-t-s.aspx

(Also some extra links in the comments)

Answer 2

You can direct cast while iterating:

IList myList = (IList)moduleObj.GetType().GetMethod(
             "ChildItems").Invoke(moduleObj, new object[] { });
foreach (IItemListable o in myList)
{

}

---

Edit: I would better mark ChildItems as virtual in the base then you could write

public override List<Article> ChildItems()
{
  return base.ChildItems().Where(a => a.IsLive).ToList();
}

and

var myList = moduleObj.ChildItems();
foreach (IItemListable o in myList)
{
}

without any need to cast, avoiding the use of the new keyword and without having to use reflection.