C # event Delegate __c#

Code is understood by the mother   Direct open dry   

Using System;
Using System.Collections;
public delegate void addEventHandler (object sender, EventArgs e);  Declares an event delegate type public
class Listwithevent:arraylist
{public
    event addEventHandler Added;    Declares an event
    protected virtual void onchanged (EventArgs e)
    {
        if (Added!= null)
            Added (this, e);
    public override int Add (object value)
    {
        int i = base. ADD (value);
        OnChanged (eventargs.empty);
        return i;
    }
}
Class Eventmethod
{public
    void ListChanged (object sender, EventArgs e)
    {
        Console.WriteLine (" This is called when the event fires. ");
    }
Class program
{public
    static void Main ()
    {
        listwithevent List = new Listwithevent ();
        Eventmethod test = new Eventmethod ();
        list.added + = new addEventHandler (test. ListChanged);
        List.add ("Item 1");
        List.add ("Item 2");
        Console.read ();
    }

Do you understand me?

No matter, go on.

Using System;
Class Publisher
{public
    delegate void Publish ()//modifier  keyword    type   delegate name public
    event Publish Onpublish;   Defines the Pubish delegate type event public
    void issue ()     //define the method that triggers the event
    {
        if (onpublish!= null)        //event is not empty
        {
            Console.WriteLine ("Issue publication"). ");
            Onpublish ();             Event occurrence
        }
    }
class subscriber
{public
    void Receive ()
    {
        Console.WriteLine (The Subscriber has received the publication.) ");
    }
}
Class Story
{
    static void Main ()
    {
        Publisher Pub = new publisher ();
        Subscriber Sub = new Subscriber ();
        Pub.onpublish + = new Publisher.publish (sub.receive); A new delegate object (that is, an event) is stored in the object-> event of the delegate at this time, the event is not NULL, and the parameter is the method of the target object
        pub.issue ();   Trigger event                                               
        Console.read ();
    }

Wow, haha. It's okay

Come on.

Using System;
    Class Publisher//publisher {public delegate void Pubcomputer (string magazinename);
    public delegate void Publife (string magzinename);
    public event Pubcomputer Onpubcomputer;
    public event Publife Onpublife; public void Issuecomputer ()//define the method that triggers the event {if (Onpubcomputer!= null) {CONSOLE.WR Iteline ("The issue of Computer" magazine.)
            ");   Onpubcomputer ("Computer magazine");
        Event takes place with delegate pass parameter}} public void Issurelife ()//define the method that triggers the event {if (Onpublife!= null) {Console.WriteLine ("Published Life" magazine.)
            ");   Onpublife ("Life magazine");
    Event occurrence}} class Subscriber//Subscriber {private string name;
    Public Subscriber (string name) {this.name = name;
    public void Receive (string magazinename) {Console.WriteLine (name + "received" + magazinename);
        } class Story {static void Main () {publisher Pub = new publisher (); Subscriber ZS = new Subscriber ("John"); Pub.onpubcomputer + = new Publisher.pubcomputer (ZS. Receive);
        Book an event to the event Publisher subscriber ls = new Subscriber ("Dick"); Pub.onpubcomputer + = new Publisher.pubcomputer (ls.  Receive); Triggers the event to cause the associated method Pub.onpublife = = new Publisher.publife (ls. Receive); The//new operator is the object that creates a delegate

                            A new delegate object (that is, an event) is placed in the object-> event of the delegate, associated with the target object method, at which point the event is not empty  onpublife. =null

Pub.issuecomputer (); Trigger event Pub.issurelife (); Console.WriteLine (); Console.WriteLine ("One year later"); Pub.onpubcomputer-= new Publisher.pubcomputer (ls. Receive); Pub.issuecomputer (); Pub.issurelife (); Console.read (); }}

It's better now.

Another big trick ...

Using System;
Using System.Collections;
    Class Pubeventargs:eventargs {private readonly string m_magazinename;
    Private readonly string m_pubdate;
        Public Pubeventargs (String magazinename, DateTime pubdate) {m_magazinename = Magazinename;
        pubdate = new DateTime ();
    M_pubdate = Pubdate.tostring ();
        public string Magazinename//property {get {return m_magazinename;
        } public string pubdate//property {get {return m_pubdate;
    Class Publisher {public delegate void Pubcomputereventhandler (object sender, Pubeventargs e);     
    public delegate void Publifeeventhandler (object sender, Pubeventargs e);         
    public event Pubcomputereventhandler Pubcomputer;                         
    public event Publifeeventhandler Publife;                                      protected virtual void Onpubcomputer (Pubeventargs e) {                            
        Pubcomputereventhandler handler = Pubcomputer;                                                                          
            Prevents a possible thread synchronization problem if (handler!= null)//When the event bindings the corresponding method, the event is non-null {   Handler (this, e);                                                                                    
    This is Object E of the class that triggered the event is an object of the class that contains the event arguments } protected VI  rtual void Onpublife (Pubeventargs e) {Publifeeventhandler handler = Publife;
        With the same if (handler!= null) {handler (this, e); } public void Issuecomputer (string magazinename, DateTime pubdate) {Console.WriteLine ("Release" + Magazi
        Nename);
    Onpubcomputer (New Pubeventargs (Magazinename, pubdate)); public void Issuelife (string magazinename, DateTime pubdate) {CONSOLE.WRiteline ("release" + Magazinename);
    Onpublife (New Pubeventargs (Magazinename, pubdate));
    } class Subscriber {private string name;
    Public Subscriber (string name) {this.name = name; public void receive (object sender, Pubeventargs e) {Console.WriteLine (e.pubdate + "" + Name + "received" +
    E.magazinename);
        } class Story {static void Main () {publisher Pub = new publisher ();
        Subscriber ZS = new Subscriber ("John"); Pub.pubcomputer + = new Publisher.pubcomputereventhandler (ZS.
        Receive);
        Subscriber ls = new Subscriber ("Dick"); Pub.pubcomputer + = new Publisher.pubcomputereventhandler (ls.
        Receive); Pub.publife + = new Publisher.publifeeventhandler (ls.
        Receive);
        Pub.issuecomputer ("Computer Magazine", Convert.todatetime ("2010-9-15"));
        Pub.issuelife ("Life magazine", Convert.todatetime ("2010-9-15"));
        Console.WriteLine ();
        Console.WriteLine ("One year later"); Pub.pubcomputer-= new Publisher.Pubcomputereventhandler (LS.
        Receive);
        Pub.issuecomputer ("Computer Magazine", Convert.todatetime ("2011-9-15"));
        Pub.issuelife ("Life magazine", Convert.todatetime ("2011-9-15"));
    Console.read ();
 }
}

The. NET Framework is named 1, the name of the event should use Pascal casing naming method
2 when declaring delegate, you must use the void type as the return value. Event naming aspects For example: the event delegate for the EventName event is
Eventnameeventhandler, time to accept two incoming parameters, all named sender and E.
3 defines a class that provides event data, names classes with Eventnameeventargs, derives the class from System.EventArgs, and then adds all event-specific members
4 Implement the time criterion in the class. If the event does not require passing arguments, also declare two arguments, E
Parameter directly uses the System.EventArgs class provided by the system. If you pass the data, you inherit a class from the System.EventArgs and put the data inside.
5 provide a protected method in the class that raises the event. Named in OnEventName, which raises an event in the method.