Re: iterating over collection

[...]

> Is there a way (I can't figure one out and don't know if it's possible since
> the collection classes are all of specific object types) to somehow have one
> method into which I could pass any of the collection classes (since the are
> all based on the Dictionary<> object though with different generic objects
> even though all based on the abstract base object) and then somehow loop
> over them after casting to the base object type?

Since I don't know your exact code/classes/requirements [1], I'm not
sure, but I think the Dictionary<object, BaseObject> approach Adrian
suggested might not work for you, since a Dictionary<object, Derived>
is not assignable to a Dictionary<object, BaseObject variable or
parameter.

Because you are using generic types, it would make sense to use a
generic method as well:

T FindObject<T>(string mn, Dictionary<..., T> c) where T : BaseObject {
  foreach (T bo in c.Values {
    if (bo.MagicNamber == mn) {
      return bo;
    }
  }
  return null;
}

Alternatively, you could also use a collection library such as
Wintellect PowerCollections, which has a predefined FindFirstWhere
method, which could be used like this:

Dictionary<..., Derived> collection;
Derived d = FindFirstWhere(collection.Values, delegate(Derived element) {
  return element.MagicNumber == mn;
});

FindFirstWhere has the advantage that it can be used for any
enumerable object, not only for your dictionaries. It is probably
defined similar to the following:

T FindFirstWhere<T>(IEnumerable<T> collection, Predicate<T> criterion) {
  foreach (T element in collection) {
    if (criterion(element)) {
      return element;
    }
  }
  return default(T);
}

Regards,
Fabian

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