C # Events

/// <summary>    ///event Data/// </summary>    Internal Sealed classNewmaileventargs:eventargs {Private ReadOnlyString M_from, m_to, M_subject;  PublicNewmaileventargs (String from, string to, string subject) {M_from= from; M_to = to; M_subject =subject; }        /// <summary>        ///Sender/// </summary>         PublicString from {Get{returnM_from;} }        /// <summary>        ///Recipient/// </summary>         PublicString to {Get{returnm_to;} }        /// <summary>        ///title/// </summary>         PublicString Subject {Get{returnM_subject;} }    }    Internal classMailmanager {PrivateEventhandler<newmaileventargs>M_newmail; //Event Properties         Public EventEventhandler<newmaileventargs>NewMail {add {m_newmail+=value; } Remove {M_newmail-=value; }        }        protected Virtual voidOnnewmail (Newmaileventargs e) {//eventhandler<newmaileventargs> temp =//Interlocked.compareexchange (ref m_newmail, NULL, NULL); //if (temp! = null) Temp (this, e);            if(M_newmail! =NULL) {M_newmail.invoke ( This, E); }        }        /// <summary>        ///simulate new messages/// </summary>        /// <param name= "from" ></param>        /// <param name= "to" ></param>        /// <param name= "Subject" ></param>         Public voidSimulatenewmail (String from, string to, string subject) {Newmaileventargs e=NewNewmaileventargs ( from, to, subject);        Onnewmail (e); }    }    /// <summary>    ///Fax/// </summary>    Internal Sealed classFax { PublicFax (mailmanager mm) {mm. NewMail+=faxmsg; }        Private voidfaxmsg (Object sender, Newmaileventargs e) {Console.WriteLine ("Fax e-mail information:"); Console.WriteLine ("from={0}, To={1}, subject={2}", E.from, e.to, E.subject); }         Public voidUnregister (mailmanager mm) {mm. NewMail-=faxmsg; }    }    Internal Sealed classPager { PublicPager (mailmanager mm) {mm. NewMail+=Sendmsgtopager; }        Private voidSendmsgtopager (Object sender, Newmaileventargs e) {Console.WriteLine ("Send mail to pager:"); Console.WriteLine ("from={0}, To={1}, subject={2}", E.from, e.to, E.subject); }         Public voidUnregister (mailmanager mm) {mm. NewMail-=Sendmsgtopager; }    }

Client:

  Static voidMain (string[] args) {            //Construct a Mailmanager objectMailmanager mm =NewMailmanager (); //Construct a Fax object passing it the Mailmanager objectFax Fax =NewFax (mm); //Construct a Pager object passing it the Mailmanager objectPager Pager =NewPager (mm); //simulate an incoming mail messageMm. Simulatenewmail ("Jeffrey","Kristin","I Love you!"); //Force the Fax object to unregister itself with the MailmanagerFax.            Unregister (mm); //simulate an incoming mail messageMm. Simulatenewmail ("Jeffrey","Mom & Dad","Happy Birthday."); }

C # Events