Two programming methods of event in Asp.net Component Programming

Below isComponentsCode:
Using system;
Using system. Web. UI;
Using system. Web. UI. webcontrols;
Using system. componentmodel;

Namespace nseventstudy
{
Public Delegate void twoeventhandle (INT flag );

Public class eventstudy: system. Web. UI. webcontrols. webcontrol
{

/// // The first method for defining an event ////////////////////

Public event twoeventhandle twoevent;

Public void execute (INT flag)
{
Twoevent (FLAG );
}

//// // The second method for defining the event ////////////////// //

Private Static object _ process = new object ();
Public event twoeventhandle threeevent
{
Add
{
Events. addhandler (_ process, value );
}
Remove
{
Events. removehandler (_ process, value );
}
}

Public void innerexecute (INT flag)
{
Twoeventhandle handle = (twoeventhandle) events [_ process];
If (handle! = NULL)
{
Handle (FLAG );
}
Else
{
This. raisebubbleevent (this, null );
}
}

Protected override void render (htmltextwriter writer)
{
Base. Render (writer );
Writer. writeline ("I love you, China ");
}

}
}

TestProgram:
Using system;
Using system. collections;
Using system. componentmodel;
Using system. Data;
Using system. drawing;
Using system. Web;
Using system. Web. sessionstate;
Using system. Web. UI;
Using system. Web. UI. webcontrols;
Using system. Web. UI. htmlcontrols;

Namespace testevent
{
/// <Summary>
/// Summary of webform1.
/// </Summary>
Public class webform1: system. Web. UI. Page
{
Protected system. Web. UI. webcontrols. Button button1;
Protected nseventstudy. eventstudy eventstudy1;

Private void page_load (Object sender, system. eventargs E)
{
// Place user code here to initialize the page
}

# Code generated by region web Form Designer
Override protected void oninit (eventargs E)
{
//
// Codegen: This call is required by the ASP. NET web form designer.
//
Initializecomponent ();
Base. oninit (E );
}

/// <Summary>
/// The designer supports the required methods-do not use the code editor to modify
/// Content of this method.
/// </Summary>
Private void initializecomponent ()
{
This. eventstudy1.threeevent + = new nseventstudy. twoeventhandle (this. eventstudy1_threeevent );
This. eventstudy1.twoevent + = new nseventstudy. twoeventhandle (this. eventstudy1_twoevent );
This. button1.click + = new system. eventhandler (this. button#click );
This. Load + = new system. eventhandler (this. page_load );

}
# Endregion

Private void eventstudy1_twoevent (INT flag)
{
This. response. Write ("<SCRIPT> javascript: Alert ('twoevent event trigger ') </SCRIPT> ");
}

Private void eventstudy1_threeevent (INT flag)
{
This. response. Write ("<SCRIPT> javascript: Alert ('threeevent trigger ') </SCRIPT> ");
}

Private void button#click (Object sender, system. eventargs E)
{
This. eventstudy1.execute (6 );
This. eventstudy1.innerexecute (10 );
}
}
}