public static void StartIt()
{
TrainSignal ts = new TrainSignal();
Car car1 = new Car(ts);
Car car2 = new Car(ts);
Car car3 = new Car(ts);
Car car4 = new Car(ts);
ts.TrainIsComing();
Console.WriteLine("Set the delegate to NULL.");
ts.OnTrainSignal1 = null;
ts.OnTrainSignal2 = null;
// ts.OnTrainSignal3 = null; // this is not possible on an event
// ts.OnTrainSignal4 = null; // this bad
ts.TrainIsComing();
// ts.OnTrainSignal1(); -- Crash
// ts.OnTrainSignal2(); -- Crash
// ts.OnTrainSignal3(); // can't call the event handler directly
// ts.OnTrainSignal4(); // can't call the event handler directly
}
public Car(TrainSignal trainsignal)
{
trainsignal.OnTrainSignal1 += StopTheCar;
trainsignal.OnTrainSignal2 += StopTheCar;
trainsignal.OnTrainSignal3 += StopTheCar;
trainsignal.OnTrainSignal4 += StopTheCarArgs;
}