创建泛型类

节点类(LinkedListNode)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


namespace List
{
    public class LinkedListNode<T>
    {
        public T Value { get; private set; }
        /// <summary>
        /// 后一个节点
        /// </summary>
        public LinkedListNode<T> Next { get; internal set; }

        /// <summary>
        /// 前一个节点
        /// </summary>
        public LinkedListNode<T> Prev { get; internal set; }

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

节点列表类(LinkedList)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace List
{
    public class LinkedList<T>:IEnumerable<T>
    {
        /// <summary>
        /// 链表的头
        /// </summary>
        public LinkedListNode<T> First { get; private set; } 
        /// <summary>
        /// 链表的尾
        /// </summary>
        public LinkedListNode<T> Last { get; private set; }

        /// <summary>
        /// 增加节点
        /// </summary>
        /// <param name="node"></param>
        /// <returns></returns>
        public LinkedListNode<T> AddLast(T node)
        {
            var newNode = new LinkedListNode<T>(node); //构造节点(每个节点两个属性Next和Prev)
            if (First == null)
            {
                First = newNode;
                Last = First;
            }
            else
            {
                LinkedListNode<T> previous = Last; //链表的尾赋给节点previous
                Last.Next = newNode;   //当前链表的最后一个节点指向新节点
                Last = newNode;  //将新节点赋给链表的最后一个节点
                Last.Prev = previous; //链表的新节点指向上次添加的节点
            }
            return newNode;
        }

        /// <summary>
        /// 遍历节点
        /// </summary>
        /// <returns></returns>
        public IEnumerator<T> GetEnumerator()
        {
            LinkedListNode<T> current = First;
            while (current != null)
            {
                yield return current.Value; //yield创建一个枚举器的状态机
                current = current.Next;
            }
        }


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


    }
}

测试类(Main)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace List
{
    class Program
    {
        static void Main(string[] args)
        {
            //用int实例化
            var list = new LinkedList<int>();
            list.AddLast(1);
            list.AddLast(2);
            list.AddLast(3);

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

            //用string实例化
            var list1 = new LinkedList<string>();
            list1.AddLast("first");
            list1.AddLast("second");
            list1.AddLast("third");

            foreach (string str in list1)
            {
                Console.WriteLine(str);
            }

        }
    }
}

运行结果