Limit collection count

I am trying to write a reusable business rule that would take an editable collection property and an int value and add a broken rule to my root if the count of the collection is greater than the value.

So far, I have written the following business rule but I was hoping you can help me optimize it. Somehow it doesn't feel pretty. I would rather specify the type of the collection which is specified when the property is registered than that of the item.  All I really need to get out of all this is the count of the collection (regardless of the item type).

I am using CSLA 4.3.12

Thanks

publicclassCollectionMaxCountRule<C> : PropertyRule

{

privateint MaxCount { get; set; }

public CollectionMaxCountRule(IPropertyInfo primaryProperty, int maxCount): base(primaryProperty)

      {

MaxCount = maxCount;

PrimaryProperty = primaryProperty;

InputProperties = newList<IPropertyInfo>() { primaryProperty };

AffectedProperties.Add(primaryProperty);

}

protectedoverridevoid Execute(RuleContext context)

{

ICollection<C> _list = (ICollection<C>)context.InputPropertyValues[PrimaryProperty];

if (_list.Count > MaxCount)

context.AddErrorResult(PrimaryProperty, string.Format("{0} {1}", ResourceFiles.LibraryResources.CollectionMaxCountRule_Error_MaxCount, MaxCount.ToString()));

}

}

 It is added using the following:

BusinessRules.AddRule(

newCollectionMaxCountRule<CostEstimate>(CostEstimateCollectionProperty, int.Parse(ConfigurationManager.AppSettings["MaxCostEstimateCount"])));