DOTA版设计模式——命令

命令模式看起来好像简单些，实际还是十分复杂的。
代码比较简单，所有的Command只要继承了ICommand接口即可。
    public interface ICommand
    {
        object Execute();
    }
具体的Command类见完整代码。Command对象在构造函数中定义操作的对象，Execute方法调用构造函数中定义的对象。本示例缺少了Undo的实现，只要在执行命令时把命令记录下来，执行Undo时进行反操作即可。
UML图：

测试代码：
            DotaPatternLibrary.Command.ControlUI control = new DotaPatternLibrary.Command.ControlUI();
            DotaPatternLibrary.Command.Peasent peasent = new DotaPatternLibrary.Command.Peasent();
            DotaPatternLibrary.Command.ICommand command = new DotaPatternLibrary.Command.BuildAltar(peasent);
            control.AddCommand("ba", command);
            command = new DotaPatternLibrary.Command.BuildBarracks(peasent);
            control.AddCommand("bb", command);
            control.PressButton("ba");
            object o = control.PressButton("bb");
            DotaPatternLibrary.Command.Barracks bbObj = o as DotaPatternLibrary.Command.Barracks;
            command = new DotaPatternLibrary.Command.ProductSoldier(bbObj);
            control.AddCommand("ps", command);
            control.PressButton("ps");
完整代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

using DotaCommon;

namespace DotaPatternLibrary.Command
{
    public class ControlUI
    {
        private Hashtable commands;
        public ControlUI()
        {
            commands = new Hashtable();
        }
        public void AddCommand(string button, ICommand command)
        {
            commands.Add(button, command);
        }

        public object PressButton(string button)
        {
            return ((ICommand)commands[button]).Execute();
        }
    }

    public interface ICommand
    {
        object Execute();
    }

    public class BuildAltar : ICommand
    {
        Peasent peasent;
        public BuildAltar(Peasent peasent)
        {
            this.peasent = peasent;
        }

        #region ICommand 成员

        public object Execute()
        {
            return peasent.BuildAltar();
        }

        #endregion
    }

    public class UnBuildAltar : ICommand
    {
        Peasent peasent;
        public UnBuildAltar(Peasent peasent)
        {
            this.peasent = peasent;
        }

        #region ICommand 成员

        public object Execute()
        {
            return peasent.UnBuildAltar();
        }

        #endregion
    }

    public class BuildBarracks : ICommand
    {
        Peasent peasent;
        public BuildBarracks(Peasent peasent)
        {
            this.peasent = peasent;
        }

        #region ICommand 成员

        public object Execute()
        {
            return peasent.BuildBarracks();
        }

        #endregion
    }

    public class UnBuildBarracks : ICommand
    {

        Peasent peasent;
        public UnBuildBarracks(Peasent peasent)
        {
            this.peasent = peasent;
        }

        #region ICommand 成员

        public object Execute()
        {
            return peasent.UnBuildBarracks();
        }

        #endregion
    }

    public class ProductSoldier : ICommand
    {
        Barracks barracks;
        public ProductSoldier(Barracks barracks)
        {
            this.barracks = barracks;
        }
        #region ICommand 成员

        public object Execute()
        {
            return barracks.ProductSoldier();
        }

        #endregion
    }

    public class UnProductSoldier : ICommand
    {
        Barracks barracks;
        public UnProductSoldier(Barracks barracks)
        {
            this.barracks = barracks;
        }
        #region ICommand 成员

        public object Execute()
        {
            return barracks.UnProductSoldier();
        }

        #endregion
    }

    public class Peasent
    {
        public Alltar BuildAltar()
        {
            LandpyForm.Form.OutputResult("BuildAltar");
            return new Alltar();
        }

        public object UnBuildAltar()
        {
            LandpyForm.Form.OutputResult("Undo BuildAltar");
            return null;
        }

        public object BuildBarracks()
        {
            LandpyForm.Form.OutputResult("BuildBarracks");
            return new Barracks();
        }

        public object UnBuildBarracks()
        {
            LandpyForm.Form.OutputResult("Undo BuildBarracks");
            return null;
        }
    }

    public class Alltar
    {
        public void ProductHero()
        {
            LandpyForm.Form.OutputResult("ProductHero");
        }
        public void UnProductHero()
        {
            LandpyForm.Form.OutputResult("Undo ProductHero");
        }
    }

    public class Barracks
    {
        public object ProductSoldier()
        {
            LandpyForm.Form.OutputResult("ProductSoldier");
            return new Soldier();
        }
        public object UnProductSoldier()
        {
            LandpyForm.Form.OutputResult("Undo ProductSoldier");
            return null;
        }
    }

    public class Soldier
    {
    }
}