1 /*
2 * 网上商店中如果商品（product）在名称（name）、价格（price）等
3 * 方面有变化，系统能自动通知会员，将是网上商店区别传统商店的一
4 * 大特色。应用外观模式，用C#控制台应用程序改进设计。
5 */
6 using System;
7 using System.Collections.Generic;
8 using System.Linq;
9 using System.Text;
10
11 namespace Observer
12 {
13 //观察者-会员类
14 class Vip
15 {
16 private string name;
17 private string rcv_msg;
18 private ShopSystem shopsystem;
19
20 public Vip(ShopSystem shopsystem,
string name)
21 {
22 this.shopsystem =
shopsystem;
23 this.name =
name;
24 }
25 public void RcvMsg()
26 {
27 rcv_msg =
shopsystem.SndMsg;
28 Console.WriteLine(
"尊敬的{0}，{1}，预购从速哦~亲~",name,rcv_msg);
29 }
30 }
31 //通知者-系统类
32 class ShopSystem
33 {
34 private string snd_msg;
35 private IList<Vip> vips =
new List<Vip>
();
36 public string SndMsg
37 {
38 get {
return snd_msg; }
39 set { snd_msg =
value; }
40 }
41 public void Attach(Vip vip)
42 {
43 vips.Add(vip);
44 }
45 public void Detach(Vip vip)
46 {
47 vips.Remove(vip);
48 }
49 public void Notify()
50 {
51 foreach (Vip vip
in vips)
52 {
53 vip.RcvMsg();
54 }
55 }
56 }
57 //Client-商品类
58 class Product
59 {
60 private string name;
61 private string price;
62 public Product(
string name,
string price)
63 {
64 this.name =
name;
65 this.price =
price;
66 }
67 public void SetName(ShopSystem shopsystem,
string name)
68 {
69 shopsystem.SndMsg=(
"【"+
this.name+
"】改名为【"+name+
"】");
70 shopsystem.Notify();
71 this.name =
name;
72 }
73 public void SetPrice(ShopSystem shopsystem,
string price)
74 {
75 shopsystem.SndMsg = (
"【" + name +
"】价格由【" +
this.price +
"】调整为【" + price +
"】");
76 shopsystem.Notify();
77 this.price =
price;
78 }
79 }
80 class Program
81 {
82 static void Main(
string[] args)
83 {
84 Product pro1 =
new Product(
"北京方便面",
"0.7￥");
85 Product pro2 =
new Product(
"武汉热干面",
"2.0￥");
86 ShopSystem shopsystem =
new ShopSystem();
87 shopsystem.Attach(
new Vip(shopsystem,
"魏艾皮"));
88 shopsystem.Attach(
new Vip(shopsystem,
"卫蔼霹"));
89
90 pro1.SetName(shopsystem,
"超级北京方便面");
91 pro2.SetName(shopsystem,
"无敌武汉热干面");
92 pro1.SetPrice(shopsystem,
"0.5￥");
93 pro1.SetPrice(shopsystem,
"1.5￥");
94 }
95 }
96 }
转载于:https://www.cnblogs.com/CheeseZH/archive/2012/05/18/2508405.html
