Declaring Delegates

A delegate is defined via the Delegate keyword followed by the method signature it needs to implement. Such a signature can be referred to as a Sub or as a Function and might or might not receive arguments. The following code defines a delegate that can handle a reference to methods able to check an email address, providing the same signature of the delegate:

Public Delegate Function IsValidMailAddress(ByVal emailAddress _                                            As String) As Boolean

Delegates Support Generics

Delegates support generics, meaning that you can define a Delegate Function DelegateName(Of T) or Delegate Sub DelegateName(Of T).

Notice that IsValidMailAddress is a type and not ...

Get Visual Basic 2015 Unleashed now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.