We'll create a class called Disabled Events Scope: This class is simple and to the point.We inherit SPItem Event Receiver and IDisposable, SPItem Event Receiver will give us access to the base properties in the event receiver and IDisposable will give us a Dispose method (which comes in handy in a moment).
So, if you add a button to a Details View with Command Name="Update", then the update will be initiated when the command is clicked.For example, if you have an Item Added event on a list and you write code within it to add an item, you can put that code in a Disable Event Receivers() ... When you add a new item, only the Item Adding() event is raised.However, in cases where Explorer View is used, both the Item Adding() and Item Updating events are raised.4) Synch Event Handler can be used to Add/Modify the values of list fields while using Asynch Event Handler its not possible as it fires after the completion of event. Let me give you example, I have lists like Program, Sub Program. So when end user is going to delete Program ,all related its subprogram must be deleted. Once parent is deleted we have to delete all its children. For any listeventhandler first we have to Implements a related Interface depends on requirement .