[Custom event] A full custom event #Event

CustomEvent.vb

Public Class FooBar
    Public Delegate Sub FooBarChanged(sender As Object, e As FooBarEventArgs)
	Public Event OnFooBarChange As FooBarChanged
    
    Private Sub RaiseEvent()
    	RaiseEvent OnFooBarChange(Me, new FooBarEventArgs(123))
    End Sub
End Class

CustomEventArgs.vb

Public Class FooBarEventArgs
    Inherits EventArgs

    Public ReadOnly Property MyProperty As Integer

    Friend Sub New(ByVal MyProperty As Integer)
        MyBase.New()

        Me.MyProperty = MyProperty
    End Sub

End Class