C#

代码：

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

namespace 简单工厂模式
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("请输入你要的电脑：");
            string brand = Console.ReadLine();
            Notepad nt = GC(brand);
            nt.SayHello();
            Console.ReadKey();
        }


        /// <summary>
        /// 简单工厂模式
        /// </summary>
        /// <param name="brand"></param>
        /// <returns></returns>
        public static Notepad GC(string brand)
        {
            Notepad nt = null;

            switch (brand)
            {
                //核心代码
                case "Lenovo": nt = new Lenovo(); break;
                case "Acer": nt = new Acer(); break;
                case "IBM": nt = new IBM(); break;
                default:break;
            }

            return nt;
        }
    }

    /// <summary>
    /// 父类
    /// </summary>
    public abstract class Notepad
    {
        public abstract void SayHello();
    }

    /// <summary>
    /// 宏基
    /// </summary>
    public class Acer : Notepad
    {
        public override void SayHello()
        {
            Console.WriteLine("我是宏基！");
        }
    }

    /// <summary>
    /// 联想
    /// </summary>
    public class Lenovo : Notepad
    {
        public override void SayHello()
        {
            Console.WriteLine("我是联想！");
        }
    }

    /// <summary>
    /// IBM
    /// </summary>
    public class IBM : Notepad 
    {
        public override void SayHello()
        {
            Console.WriteLine("我是IBM！");
        }
    }
}