17. Observer mode (Observer pattern)

usingSystem;usingSystem.Collections.Generic;namespaceconsoleapplication10{/// <summary>    ///In the process of software building, we need to establish a "notification dependency" for some objects///--The state of an object (the target object) is changed, and all dependent objects (the Observer object) are notified. ///if such dependencies are too tight, the software will not be able to withstand changes very well. Using object-oriented technology, you can weaken this dependency,///and to form a stable dependency relationship.    So as to realize the loose coupling of software architecture. /// </summary>    classProgram {Static voidMain (string[] args) {Stock ms=NewMicrosoft ("Microsoft",120.00); Ms. Addobserver (NewInvestor ("Jom")); Ms. Addobserver (NewInvestor ("Terrylee")); Ms.            Update ();        Console.ReadLine (); }    }    /// <summary>    ///Stock/// </summary>     Public Abstract classStock {PrivateList<iobserver> observers =NewList<iobserver>(); PrivateString _symbol; Private Double_price;  PublicStock (String symbol,DoublePrice ) {             This. _symbol =symbol;  This. _price =Price ; }        /// <summary>        ///Send Message/// </summary>         Public voidUpdate () {foreach(IObserver obinchobservers) {ob. SendData ( This); }        }         Public voidAddobserver (IObserver observer) {observers.        ADD (Observer); }         Public voidRemoveobserver (IObserver observer) {observers.        REMOVE (Observer); }         PublicString Symbol {Get{return_symbol;} }         Public DoublePrice {Get{return_price;} }    }    /// <summary>    ///Microsoft's stock/// </summary>     Public classMicrosoft:stock { PublicMicrosoft (String symbol,DoublePrice ):Base(symbol, price) {}} Public InterfaceIObserver {voidSendData (stock stock); }     Public classInvestor:iobserver {Private string_name;  PublicInvestor (stringname) {             This. _name =name; }         Public voidSendData (stock stock) {Console.WriteLine ("notified {0} of {1} ' s"+"Change to {2:C}", _name, stock. Symbol, stock.        Price); }    }}

usingSystem;usingSystem.Collections.Generic;namespaceconsoleapplication10{/// <summary>    ///In the process of software building, we need to establish a "notification dependency" for some objects///--The state of an object (the target object) is changed, and all dependent objects (the Observer object) are notified. ///if such dependencies are too tight, the software will not be able to withstand changes very well. Using object-oriented technology, you can weaken this dependency,///and to form a stable dependency relationship.    So as to realize the loose coupling of software architecture. /// </summary>    classProgram {Static voidMain (string[] args) {Stock Stock=NewStock ("Microsoft",120.00); Investor Investor=NewInvestor ("Jom"); Investor Investor1=NewInvestor ("Sam"); Stock. Notifyevent+=NewNotifyeventhandler (investor.            SendData); Stock. Notifyevent+=NewNotifyeventhandler (Investor1.            SendData); Stock.            Update ();        Console.ReadLine (); }    }     Public Delegate voidNotifyeventhandler (Objectsender);  Public classStock { PublicNotifyeventhandler notifyevent; PrivateString _symbol; Private Double_price;  PublicStock (String symbol,DoublePrice ) {             This. _symbol =symbol;  This. _price =Price ; }         Public voidUpdate () {onnotifychange (); }         Public voidOnnotifychange () {if(Notifyevent! =NULL) {notifyevent ( This); }        }         PublicString Symbol {Get{return_symbol;} }         Public DoublePrice {Get{return_price;} }    }     Public classInvestor {Private string_name;  PublicInvestor (stringname) {             This. _name =name; }         Public voidSendData (Objectobj) {            if(obj isStock) {Stock Stock=(Stock) obj; Console.WriteLine ("notified {0} of {1} ' s"+"Change to {2:C}", _name, stock. Symbol, stock.            Price); }        }    }}

17. Observer mode (Observer pattern)