设计模式之命令模式

/// <summary>
/// 接收者类，知道如何实施与执行一个请求相关的操作，任何类都可能作为一个接收者。
/// </summary>
public class Receiver
{
    /// <summary>
    /// 真正的命令实现
    /// </summary>
    public void Action()
    {
        Console.WriteLine("Execute request!");
    }
}

/// <summary>
/// 抽象命令类，用来声明执行操作的接口
/// </summary>
public interface ICommand
{
    void Execute();
}

/// <summary>
/// 具体命令类，实现具体命令。
/// </summary>
public class ConcereteCommand : ICommand
{
    // 具体命令类包含有一个接收者，将这个接收者对象绑定于一个动作
    private Receiver receiver;

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

    /// <summary>
    /// 说这个实现是“虚”的，因为它是通过调用接收者相应的操作来实现Execute的
    /// </summary>
    public void Execute()
    {
        receiver.Action();
    }
}

/// <summary>
/// 调度类，要求该命令执行这个请求
/// </summary>
public class Invoker
{
    private ICommand command;

    /// <summary>
    /// 设置命令
    /// </summary>
    /// <param name="command"></param>
    public void SetCommand(ICommand command)
    {
        this.command = command;
    }

    /// <summary>
    /// 执行命令
    /// </summary>
    public void ExecuteCommand()
    {
        command.Execute();
    }
}

/// <summary>
/// 调用
/// </summary>
/// <param name="args"></param>
static void Main(string[] args)
{
    Receiver receiver = new Receiver();
    ICommand command = new ConcereteCommand(receiver);
    Invoker invoker = new Invoker();

    invoker.SetCommand(command);
    invoker.ExecuteCommand();

    Console.ReadLine();
}