Raise Events : Event « Event « VB.Net Tutorial






Module Module1

    Dim WithEvents ValueInfo As New Value()

    Class Value
        Public Event ValueUp(ByVal Amount As Double)
        Public Event ValueDown(ByVal Amount As Double)
        Public Event Result(ByVal Amount As Double, ByVal AnnounceDate As DateTime)

        Public Sub GenerateEvents()
            RaiseEvent ValueUp(2)
            RaiseEvent ValueDown(-5.5)
            RaiseEvent Result(1.25, Now())
        End Sub
    End Class

    Sub PriceGoingUp(ByVal Price As Double)
        Console.WriteLine("Up: " & Price)
    End Sub

    Sub PriceGoingDown(ByVal Price As Double)
        Console.WriteLine("Down: " & Price)
    End Sub

    Sub ResultAnnouncement(ByVal Amount As Double, ByVal AnnounceDate As DateTime)
        Console.WriteLine("Result: " & Amount & " " & AnnounceDate)
    End Sub


    Sub Main()
        AddHandler ValueInfo.ValueUp, AddressOf PriceGoingUp
        AddHandler ValueInfo.ValueDown, AddressOf PriceGoingDown
        AddHandler ValueInfo.Result, AddressOf ResultAnnouncement

        ValueInfo.GenerateEvents()
    End Sub


End Module
Up: 2
Down: -5.5
Result: 1.25 11/05/2007 9:33:43 PM








11.1.Event
11.1.1.Raise Events
11.1.2.Multiple Event Handler
11.1.3.Event handler
11.1.4.Subclass EventArgs to create your own event arguments
11.1.5.Inherit Event
11.1.6.Custom event handler
11.1.7.WithEvents and Event method
11.1.8.Add and remove event handlerAdd and remove event handler
11.1.9.Handle events from more than one componentsHandle events from more than one components
11.1.10.Add, remove event handler to/from ToggleButtonAdd, remove event handler to/from ToggleButton
11.1.11.Use one method to handle more than one RadioButton click eventUse one method to handle more than one RadioButton click event
11.1.12.Get event sender typeGet event sender type
11.1.13.Instantiating the Action<(Of <(T>)>) delegate rather than explicitly defining a new delegate and assigning a named method