public static BeepWirelessSpeaker()
{
WirelessSpeaker w = new WirelessSpeaker();
IBeepSpeakers wirelessSpeakerBeeper =
new IBeepSpeakers(w, s => ((WiredSpeaker)s).IsTransmitterOn = true);
wirelessSpeakerBeeper.BeepTheSpeaker();
}
public static BeepWiredSpeaker()
{
Speaker s = new Speaker();
IBeepSpeakers wiredSpeakerBeeper =
new IBeepSpeakers(s, s => ((Speaker)s).IsPlugged = true);
wiredSpeakerBeeper.BeepTheSpeaker();
}
public static BeepWirelessSpeaker_Version1()
{
// This is a valid assignment.
Speaker s = new WirelessSpeaker();
IBeepSpeakers wirelessSpeakerBeeper = new IBeepSpeakers(s);
// This call will fail!
// In WirelessSpeaker, we _OVERRODE_ the Beep method to check
// that TransmitterIsOn is true. But, IBeepSpeakers doesn't
// know anything _specifically_ about WirelessSpeaker speakers,
// so it can't set this property!
// Therefore, an InvalidOperationException will be thrown.
wirelessSpeakerBeeper.BeepTheSpeaker();
}
// We pass in an actual speaker object.
// This method works as expected.
public static BeepWiredSpeaker()
{
Speaker s = new Speaker();
IBeepSpeakers wiredSpeakerBeeper = new IBeepSpeakers(s);
wiredSpeakerBeeper.BeepTheSpeaker();
}
