1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Text;
5 using System.Threading.Tasks;
6
7
8 namespace Wrox.ProCSharp.Delegates
9 {
10 public class CarInfoEventArgs:EventArgs
11 {
12 public CarInfoEventArgs(string car)
13 {
14 this.Car = car;
15 }
16
17 public string Car {get; private set;}
18 }
19
20 public class CarDealer
21 {
22 public event EventHandler<CarInfoEventArgs> NewCarInfo; //泛型委托,约定:第一个参数是一个对象,包含事件的发送者,第二个参数提供了事件的相关信息
23
24 public void NewCar(string car)
25 {
26 Console.WriteLine("CarDealer, new car{0}", car);//显示car信息
27
28 RaiseNewCarInfo(car);
29 }
30
31 protected virtual void RaiseNewCarInfo(string car)
32 {
33 EventHandler<CarInfoEventArgs> newCarInfo = NewCarInfo;
34 if (newCarInfo != null)
35 {
36 newCarInfo(this, new CarInfoEventArgs(car));
37 }
38 }
39 }
40 }
41
42 ///////////////////////////////////////////////////////////////////////////////////
43
44 private delegate EventHandler<CarInfoEventArgs> newCarInfo;
45 public event EventHandler<CarInfoEventArgs> NewCarInfo
46 {
47 add
48 {
49 newCarInfo += value;
50 }
51 remove
52 {
53 newCarInfo -= value;
54 }
55 }
56
57 ////////////////////////////////////////////////////////////////////////
58
59 using System;
60
61 namespace Wrox.ProCSharp.Delegates
62 {
63 public class Consumer
64 {
65 private string name;
66
67 public Consumer(string name)
68 {
69 this.name = name;
70 }
71
72 public void NewCarIsHere(object sender, CarInfoEventArgs e)
73 {
74 Console.WriteLine("{0}: car {1} is new", name, e.Car);
75 }
76 }
77 }
78
79 ////////////////////////////////////////////////////////////////////////
80
81 namespace Wrox.ProCSharp.Delegates
82 {
83 class Program
84 {
85 static void Main()
86 {
87 var dealer = new CarDealer();
88
89 var michael = new Consumer("Michael");
90 dealer.NewCarInfo += michael.NewCarIsHere;
91
92 dealer.NewCar("Ferrari");
93
94 var sebastian = new Consumer("Sebastian");
95 dealer.NewCarInfo += sebastian.NewCarInfo;
96
97 dealer.NewCar("Mercedes");
98
99 dealer.NewCarInfo -=michael.NewCarIsHere;
100
101 dealer.NewCar("Red Bull Racing");
102 }
103 }
104 }
