接口IEnumerable的使用实例

    public class LinkedList : IEnumerable
    {
        public LinkedListNode First { get; private set; }
        public LinkedListNode Last { get; private set; }

        public LinkedListNode AddLast(object node)
        {
            var newNode = new LinkedListNode(node);
            if (First == null)
            {
                First = newNode;
                Last = First;
            }
            else
            {
                Last.Next = newNode;
                Last = newNode;
            }
            return newNode;
        }

        public IEnumerator GetEnumerator()
        {
            LinkedListNode current = First;
            while (current != null)
            {
                yield return current.Value;
                current = current.Next;
            }
        }
    }

 

    public class LinkedListNode
    {
        public LinkedListNode(object value)
        {
            this.Value = value;
        }

        public object Value { get; private set; }

        public LinkedListNode Next { get; internal set; }
        public LinkedListNode Prev { get; internal set; }
    }

 

    class Program
    {
        static void Main()
        {
            var list1 = new LinkedList();
            list1.AddLast(2);
            list1.AddLast(4);
            list1.AddLast("6");

            foreach (int i in list1)
            {
                Console.WriteLine(i);
            }

        }
    }

再来一个泛型的。

   public class LinkedListNode
   {
      public LinkedListNode(T value)
      {
         this.Value = value;
      }
   
      public T Value { get; private set; }
      public LinkedListNode Next { get; internal set; }
      public LinkedListNode Prev { get; internal set; }
   }

    public class LinkedList : IEnumerable
    {
        public LinkedListNode First { get; private set; }
        public LinkedListNode Last { get; private set; }

        public LinkedListNode AddLast(T node)
        {
            var newNode = new LinkedListNode(node);
            if (First == null)
            {
                First = newNode;
                Last = First;
            }
            else
            {
                Last.Next = newNode;
                Last = newNode;
            }
            return newNode;
        }

        public IEnumerator GetEnumerator()
        {
            LinkedListNode current = First;

            while (current != null)
            {
                yield return current.Value;
                current = current.Next;
            }
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }

 

    class Program
    {
        static void Main()
        {
            var list2 = new LinkedList();
            list2.AddLast(1);
            list2.AddLast(3);
            list2.AddLast(5);

            foreach (int i in list2)
            {
                Console.WriteLine(i);
            }

            var list3 = new LinkedList();
            list3.AddLast("2");
            list3.AddLast("four");
            list3.AddLast("foo");

            foreach (string s in list3)
            {
                Console.WriteLine(s);
            }


        }
    }

 

转自《Professional C# 4 and .neT 4》