分享程序员开发的那些事...
更新时间：2022-09-21 23:04:28
观察模式：定义对象间的一种一对多的依赖关系,当一个对象的状态发生改变时, 所有依赖于它的对象都得到通知并被自动更新;
以下的列子含义：当车站要求指定的列车发车，所有在站内的列表均得到发车通知！
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace PatternProject
{ public interface ITrain
{
string From
{ get; set; }
string To
{ get; set; }
DateTime StartingDateTime
{ get; set; }
void Start(ITrain train);
}
public interface IStation
{
void AddTrain(ITrain train);
void CancelTrain(ITrain train);
void StartNotify(ITrain train);
}
public class Station : IStation
{
List<ITrain> _trainList = new List<ITrain>();
public void AddTrain(ITrain train)
{
_trainList.Add(train);
}
public void CancelTrain(ITrain train)
{
_trainList.Remove(train);
}
public void StartNotify(ITrain train)
{
foreach (ITrain t in _trainList)
{
t.Start(train);
}
}
}
public class Train : ITrain
{
public string From
{ get; set; }
public string To
{ get; set; }
public DateTime StartingDateTime
{ get; set; }
public Train(string from, string to, DateTime startingDateTime)
{
this.From = from;
this.To = to;
this.StartingDateTime = startingDateTime;
}
public bool IsCurrent(ITrain train)
{
if (train.From == this.From && train.To == this.To && train.StartingDateTime == this.StartingDateTime)
{
return true;
}
else
{
return false;
}
}
public void Start(ITrain train)
{
Console.WriteLine("{0}开往{1}列车收到通知：",this.From,this.To);
if (IsCurrent(train))
{
Console.WriteLine("从{0}开往{1}的列车,于{2}开车，敬请注意！", this.From, this.To, this.StartingDateTime);
}
else
{
Console.WriteLine("还未到开车时间，敬请稍候！");
}
}
}
}<br><br> |
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace PatternProject
{ class Program
{
static void Main(string[] args)
{
Station station = new Station();
station.AddTrain(new Train("北京", "上海", new DateTime(2014, 5, 1)));
station.AddTrain(new Train("北京", "武汉", new DateTime(2014, 3, 1)));
station.AddTrain(new Train("武汉", "上海", new DateTime(2014, 2, 1)));
station.AddTrain(new Train("上海", "南京", new DateTime(2014, 8, 1)));
Train t = new Train("北京", "武汉", new DateTime(2014, 3, 1));
station.StartNotify(t);
Console.ReadKey();
}
}
} |
本文转自 梦在旅途 博客园博客，原文链接： http://www.cnblogs.com/zuowj/p/3504852.html ，如需转载请自行联系原作者