How does Asp.net dynamically call the processing method of Object events?

 

For example, how can I call the method specified by onpageindexchanging for a gridview? The premise is that I don't know what this method is.

Question added:

Thank you for your answers.
The above is just an example. I Don't Want To pagination, but just want to dynamically call the method specified by the event Delegate. It should be related to reflection, but no relevant method is found. For example, if I have a textbox, I don't know what the ontextchange method is, but I still want to call this method because the parameters of the event Delegate are fixed, so this idea should be feasible, but I don't know the specific method.
========================================================== ================================== // Define the event container. If your inherited class has one, you do not need to define it.
Private EventHandlerList _ events;
Protected EventHandlerList Events
{
Get
{
If (_ events = null)
{
_ Events = new eventhandlerlist ();
}
Return _ events;
}
}
// Define a delegate in the class
Public Delegate void myhandler (Object sender, event E );

// Define the event key
Private Static readonly object myobj = new object ();

// Use this delegate to define the event

Public event myhandler myevent
{
Add
{
Events. addhandler (myobj, value );
}
Remove
{
Events. removehandler (myobj, value );
}
}

// Use the event Method
Private void onmymethodhandler (event E)
{
Myhandler handler = (myhandler) events [myobj];
If (handler! = NULL)
{
Handler (this, e );
}
}

Public void mymethod2 (){

// Call this method where you want to use it
Onmymethodhandler (event. Empty );
}

// This is what you did not know the specified method. B may be used by others.
Public void B (Object sender, event e ){
}
// Others use this method
// If you are a Class
A A = new ();
A. myevent + = new myhandler (B );

// When you run mymethod2, its B will run.

// If you want B to return a value, you need to define the event yourself. You can use e to communicate with B.

========================================================== ======================================
Front-end:
<Asp: gridview id = "gridview1" runat = "server" onpageindexchanging = "AA">
</ASP: gridview>

Background:
Public viod AA (Object sender, gridviewpageeventargs e ){
Gridview1.pageindex = E. newpageindex;
}

Or
Front-end:
<Asp: gridview id = "gridview1" runat = "server">
</ASP: gridview>
Background
Protected void page_load (Object sender, eventargs e ){
Gridview1.pageindexchanging + = new gridviewpageeventhandler (AA );
}
Public viod AA (Object sender, gridviewpageeventargs e ){
Gridview1.pageindex = E. newpageindex;
}