设计模式：命令模式

namespace CommandDesign
{
    public abstract class Command
    {
        protected Receiver receiver;
        public Command(Receiver receiver)
        {
            this.receiver = receiver;
        }
        public abstract void Execute();
    }
    public class ConcreteCommand : Command
    {
        public ConcreteCommand(Receiver receiver) : base(receiver) { }
        public override void Execute()
        {
            receiver.Action();
        }
    }
    public class Invoker
    {
        private Command command;
        public void SetCommand(Command command)
        {
            this.command = command;
        }
        public void ExecuteCommand()
        {
            command.Execute();
        }
    }
    public class Receiver
    {
        public void Action()
        {
            Console.WriteLine("执行请求！");
        }
    }
}

            Receiver r = new Receiver();
            Command c = new ConcreteCommand(r);
            Invoker i = new Invoker();
            i.SetCommand(c);
            i.ExecuteCommand();