Design Patterns 23 - 命令模式

abstract class Command {
    protected Receiver receiver;

    public Command(Receiver receiver) {
        this.receiver = receiver;
    }

    abstract public void Execute();
}

class ConcreteCommand :  Command {
    public ConcreteCommand(Receiver receiver) : base(receiver) {
    }

    public override void Execute() {
        receiver.Action();
    }
}

class Invoker {
    private Command command;

    public void SetCommand(Command command) {
        this.command = command;
    }

    public void ExecuteCommand() {
        command.Execute();
    }
}

class Receiver {
    public void Action {
        // todo
    }
}

public static void Main(string[] agrs) {
    Receiver receiver = new Receiver();
    Command command = new ConcreteCommand(receiver);
    Invoker invoker = new Invoker();
    invoker.SetCommand(command);
    invoker.ExecuteCommand();
}