using System;using System.Collections.Generic;using System.Text;namespace Pattern.Observer
{
/// <summary>
/// Message实体类
/// </summary> public class MessageModel { /// <summary> /// 构造函数 /// </summary> /// <param name="msg">Message内容</param> /// <param name="pt">Message发布时间</param> public MessageModel(string msg, DateTime pt) { this._message = msg; this._publishTime = pt; } private string _message; /// <summary> /// Message内容 /// </summary> public string Message { get { return _message; } set { _message = value; } } private DateTime _publishTime; /// <summary> /// Message发布时间 /// </summary> public DateTime PublishTime { get { return _publishTime; } set { _publishTime = value; } } }
}using System;using System.Collections.Generic;using System.Text;namespace Pattern.Observer{ /// <summary> /// 操作Message的接口（Observer） /// </summary> public interface IMessage { /// <summary> /// 插入Message /// </summary> /// <param name="mm">Message实体对象</param> /// <returns></returns> string Insert(MessageModel mm); }}using System;using System.Collections.Generic;using System.Text;namespace Pattern.Observer{ /// <summary> /// Sql方式操作Message（ConcreteObserver） /// </summary> public class SqlMessage : IMessage { /// <summary> /// 插入Message /// </summary> /// <param name="mm">Message实体对象</param> /// <returns></returns> public string Insert(MessageModel mm) { return "sql方式：" + mm.Message + " " + mm.PublishTime.ToString(); } }}using System;using System.Collections.Generic;using System.Text;namespace Pattern.Observer{ /// <summary> /// Xml方式操作Message（ConcreteObserver） /// </summary> public class XmlMessage : IMessage { /// <summary> /// 插入Message /// </summary> /// <param name="mm">Message实体对象</param> /// <returns></returns> public string Insert(MessageModel mm) { return "xml方式：" + mm.Message + " " + mm.PublishTime.ToString(); } }}using System;using System.Collections.Generic;using System.Text;namespace Pattern.Observer{ /// <summary> /// 抽象Message主题（Subject） /// </summary> public abstract class AbstractMessageSubject { private MessageModel _messageModel; private List<IMessage> list = new List<IMessage>(); /// <summary> /// 构造函数 /// </summary> /// <param name="mm">Message实体对象</param> public AbstractMessageSubject(MessageModel mm) { this._messageModel = mm; } /// <summary> /// 添加一个实现IMessage接口的对象 /// </summary> /// <param name="m">实现IMessage接口的对象</param> public void Attach(IMessage m) { list.Add(m); } /// <summary> /// 移除一个实现IMessage接口的对象 /// </summary> /// <param name="m">实现IMessage接口的对象</param> public void Detach(IMessage m) { list.Remove(m); } /// <summary> /// 通知所有观察者 /// </summary> /// <returns></returns> public string Notify() { string s = ""; foreach (IMessage i in list) { s += i.Insert(_messageModel); s += "<br />"; } return s; } /// <summary> /// Message发布时间 /// </summary> public DateTime PublishTime { get { return _messageModel.PublishTime; } set { _messageModel.PublishTime = value; Notify(); } } }}using System;using System.Collections.Generic;using System.Text;namespace Pattern.Observer{ /// <summary> /// Message主题（ConcreteSubject） /// </summary> public class MessageSubject : AbstractMessageSubject { /// <summary> /// 构造函数 /// </summary> /// <param name="mm">Message实体对象</param> public MessageSubject(MessageModel mm) : base(mm) { } }}using System;using System.Data;using System.Configuration;using System.Collections;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using Pattern.Observer;public partial class Observer : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { MessageSubject m = new MessageSubject(new MessageModel("插入Message", DateTime.Now)); SqlMessage sqlMessage = new SqlMessage(); XmlMessage xmlMessage = new XmlMessage(); m.Attach(sqlMessage); m.Attach(xmlMessage); // System.Threading.Thread.Sleep(1000); // 修改了PublishTime就会通知所有观察者 // m.PublishTime = DateTime.Now; Response.Write(m.Notify()); }}乐在其中设计模式(C#) - 观察者模式(Observer Pattern),布布扣,bubuko.com
乐在其中设计模式(C#) - 观察者模式(Observer Pattern)
原文：http://www.cnblogs.com/lonelyxmas/p/3590360.html
