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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！
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 | 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> |
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | 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