public IEnumerator GetEnumerator()
{
LinkListNode current = this.First;
while (current != null)
{
yield return(current.Value);
current = current.Next;
}
}
public LinkListNode Add(Object obj)
{
LinkListNode node = new LinkListNode(obj);
if (First == null)
{
First = node;
Last = node;
}
//维护next和prev，直接前驱，直接后继
else
{
LinkListNode lastNode = this.Last;
this.Last.Next = node;
this.Last = node;
node.Prev = lastNode;
}
return(node);
}