The add and remove keywords allow you to execute code whenever a delegate is added or removed from an event. Its usage is similar to the get and set keywords with properties:

public event MyDelegateType MyEvent
{
    add
    {
        // here you can use the keyword "value" to access the delegate that is being added
        ...
    }
    
    remove
    {
        // here you can use the keyword "value" to access the delegate that is being removed
        ...
    }
}

The code in the add block will be executed when a delegate is added to the event. Similarly, the code in the remove block will be executed when a delegate is removed from the event.



C# Keywords
abstract as base bool break
byte case catch char checked
class const continue decimal default
delegate do double else enum
event explicit extern false finally
fixed float for foreach goto
if implicit in int interface
internal is lock long namespace
new null object operator out
override params private protected public
readonly ref return sbyte sealed
short sizeof stackalloc static string
struct switch this throw true
try typeof uint ulong unchecked
unsafe ushort using var virtual
void volatile while
Special C# Identifiers (Contextual Keywords)
add alias async await dynamic
get global nameof partial remove
set value when where yield
Contextual Keywords (Used in Queries)
ascending by descending equals from
group in into join let
on orderby select where