Class with events VB NET

VB.NET > Class > WithEvents

WithEvents specifies that one or more declared member variables refer to an instance of a class that can raise events.

Example: class with events

 Public Class Export
        Public Event TimesUp()
        Public Sub New()
            Dim worker As New BackgroundWorker()
            AddHandler worker.DoWork, AddressOf DoWork
            AddHandler worker.RunWorkerCompleted, AddressOf bg_RunWorkerCompleted
            worker.RunWorkerAsync()
        End Sub
        Private Sub DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs)
            ' export stuff
            Thread.Sleep(5000)
        End Sub
        Private Sub bg_RunWorkerCompleted(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs)
            MsgBox("Background worker completed", vbInformation, "Background worker")
            RaiseEvent TimesUp() 'Triggers an event declared at module level within a class, form, or document.
        End Sub
    End Class

    Dim WithEvents _Export As New Export

    Private Sub handleTimesUp() Handles _Export.TimesUp
        MsgBox("TimesUp Event Raised and Handled")
    End Sub