策略模式

策略模式可以认为是根据输入要求通过多种方法得到结果，对中间计算过程的封装，可参考：http://www.cnblogs.com/chenssy/p/3295643.html，总结已经很好了，这里贴一张策略模式的结构图，用startuml自己画的：

生成c#代码为：

using System.Windows.Forms;

namespace TestFormSington
{
    public abstract class Strategy
    {
        public abstract void AlgorithmInterface();
    }
    public class Context
    {
        public Strategy strategy;
        public Context(Strategy _strategy)
        {
            strategy = _strategy;
        }
        public void ContextInterface()
        {
            strategy.AlgorithmInterface();
        }
    }
    public class ConcreteStrategyA : Strategy
    {
        public override void AlgorithmInterface()
        {
            MessageBox.Show("ConcreteStrategyA");
        }
    }
    public class ConcretStrategyC : Strategy
    {
        public override void AlgorithmInterface()
        {
            MessageBox.Show("ConcretStrategyC");
        }
    }

    public class ConcretStrategyB : Strategy
    {
        public override void AlgorithmInterface()
        {
            MessageBox.Show("ConcretStrategyB");
        }
    }
}

引用为：

 Context context = new Context(new ConcreteStrategyA());
 context.ContextInterface();