新建一个类库，然后添加一个”电脑“类 ，如下：

  public  class Computer

    {

       public Computer() { }

       public Computer(string brand,string model,double price,string color)

       {

           this.Brand = brand;

           this.Model = model;

           this.Price = price;

           this.Color = color;

       }

       public string Brand { get; set; }

       public string Model { get; set; }

       public double Price { get; set; }

       public string Color { get; set; }

       public string showinfo()

       {

           return string.Format("品牌：{0}，型号：{1}，价格：{2}，颜色：{3}", Brand, Model, Price, Color);

       }

    }

然后在新建一个控制台应用程序，添加下面的代码：

static void Main(string[] args)

        {

            List<Computer> list = GetComputer();

           

                Console.WriteLine("请输入你要购买的电脑信息，如：品牌，型号，价格，颜色");

                string query = Console.ReadLine();

                List<Computer> listquery = new List<Computer>();

                foreach (Computer item in list)

                {

                    if(query==item.Brand)

                    {

                        listquery.Add(item);

                    }

                    else if(query==item.Model)

                    {

                        listquery.Add(item);

                    }

                    else if (query == Convert.ToString(item.Price))

                    {

                        listquery.Add(item);

                    }

                    else if(query==item.Color)

                    {

                        listquery.Add(item);

                    }

                }

                Console.WriteLine("符合您的要求的电脑如下");

                foreach (Computer items in listquery)

                {

                    Console.WriteLine(items.showinfo());

                }

                Console.ReadKey();           

        }

        private static List<Computer> GetComputer()

        {

            List<Computer> listcom = new List<Computer>();

            Computer comasus = new Computer("ASUS","Y系列",4230,"蓝色");

            Computer comlenovo = new Computer("LENOVO", "E系列", 4230, "黑色");

            Computer comlenovo1 = new Computer("LENOVO", "Y系列", 4250, "黄色");

            Computer comacer = new Computer("ACER", "Y系列", 5000, "红色");

            listcom.Add(comasus);

            listcom.Add(comlenovo);

            listcom.Add(comlenovo1);

            listcom.Add(comacer);

            return listcom;

        }