public virtual void AddRange(string[] keys, T[] items)
{
if (keys.Length != items.Length)
{
throw new Exception(" ");
}
int startIndex = _items.Count;
_keys.AddRange(keys);
_items.AddRange(items);
if (ItemAddRange != null)
{
ItemAddRange(this, new KeyedCollectionAddRangeEventArgs(items, keys, startIndex));
}
if (CollectionChanged != null)
{
CollectionChanged(this, new EventArgs());
}
}