8.事件 事件发布程序

using System;

namespace Wrox.ProCSharp.Delegates
{
public class CarInfoEventArgs : EventArgs
{
public CarInfoEventArgs(string car)
{
this.Car = car;
}

public string Car { get; private set; }
}

public class CarDealer
{
public event EventHandler<CarInfoEventArgs> NewCarInfo;

public void NewCar(string car)
{
Console.WriteLine("CarDealer, new car {0}", car);

RaiseNewCarInfo(car);
}

protected virtual void RaiseNewCarInfo(string car)
{
EventHandler<CarInfoEventArgs> newCarInfo = NewCarInfo;
if (newCarInfo != null)
{
newCarInfo(this, new CarInfoEventArgs(car));
}
}
}
}

using System;

namespace Wrox.ProCSharp.Delegates
{
public class Consumer
{
private string name;

public Consumer(string name)
{
this.name = name;
}

public void NewCarIsHere(object sender, CarInfoEventArgs e)
{
Console.WriteLine("{0}: car {1} is new", name, e.Car);
}
}
}

namespace Wrox.ProCSharp.Delegates
{
class Program
{
static void Main()
{
var dealer = new CarDealer();

var michael = new Consumer("Michael");
dealer.NewCarInfo += michael.NewCarIsHere;

dealer.NewCar("Ferrari");

var nick = new Consumer("Sebastian");
dealer.NewCarInfo += nick.NewCarIsHere;

dealer.NewCar("Mercedes");

dealer.NewCarInfo -= michael.NewCarIsHere;

dealer.NewCar("Red Bull Racing");
}
}
}