none
addhandler and addressof

    Question

  • Hi,

    if I code so, I get the error: Error    1    'AddressOf' operand must be the name of a method (without parentheses).    D:\Egyeb\OTIS\OTIS\kozos\kozos.vb    36    40    OTIS

    Public Sub GreenMessage(ByVal item As BarStaticItem, ByVal szoveg As String) item.Caption = szoveg item.ImageIndex = 2 item.Appearance.BackColor = ColorTranslator.FromOle(greenstatusbar) My.Computer.Audio.Play(My.Resources.sapmsg, AudioPlayMode.Background) tmr.Interval = 500 AddHandler tmr.Tick, AddressOf tmr_tick(item) tmr.Start() End Sub Private Sub tmr_tick(ByVal item As BarStaticItem) item.Appearance.BackColor = ColorTranslator.FromOle(14206908) tmr.Stop() End Sub

    If I delete the argument, I get the error: Error    1    Argument not specified for parameter 'item' of 'Private Sub tmr_tick(item As DevExpress.XtraBars.BarStaticItem)'.    D:\Egyeb\OTIS\OTIS\kozos\kozos.vb    36    40    OTIS

    Public Sub GreenMessage(ByVal item As BarStaticItem, ByVal szoveg As String)
            item.Caption = szoveg
            item.ImageIndex = 2
            item.Appearance.BackColor = ColorTranslator.FromOle(greenstatusbar)
            My.Computer.Audio.Play(My.Resources.sapmsg, AudioPlayMode.Background)
            tmr.Interval = 500
            AddHandler tmr.Tick, AddressOf tmr_tick()
            tmr.Start()
        End Sub
        Private Sub tmr_tick(ByVal item As BarStaticItem)
            item.Appearance.BackColor = ColorTranslator.FromOle(14206908)
            tmr.Stop()
        End Sub
    So, how would it be the right way?

    Sunday, January 06, 2013 2:46 PM

Answers

  • Use the Timer's Tag property to hold the item:

      Public Sub GreenMessage(ByVal item As BarStaticItemByVal szoveg As String)
        item.Caption = szoveg
        item.ImageIndex = 2
        item.Appearance.BackColor = 
    ColorTranslator.FromOle(greenstatusbar)
        
    My.Computer.Audio.Play(My.Resources.sapmsg, AudioPlayMode.Background)
        tmr.Tag = item
        tmr.Interval = 500
        
    AddHandler tmr.Tick, AddressOf tmr_tick()
        tmr.Start()
      
    End Sub
      
    Private Sub tmr_tick(sender As Object, e As EventArgs)
        
    Dim Item As BarStaticItem = DirectCast(tmr.Tag, BarStaticItem)
        item.Appearance.BackColor = 
    ColorTranslator.FromOle(14206908)
        tmr.Stop()
      
    End Sub

    Sunday, January 06, 2013 3:46 PM
  • I just want to clarify further, instead of trying to deviate from the intended signature of an event, instead try making your value public and accessing that value from there, meanwhile, you have to use a sub that has a matching signature of the event you are assigning to it.

    Public Class Form1
        Friend WithEvents Timer1 As New Timer
        Public Item As String
        Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
            AddHandler Timer1.Tick, AddressOf Timer1_Tick
        End Sub
        Sub Timer1_Tick(sender As Object, e As EventArgs)
    
        End Sub
    End Class


    If you want something you've never had, you need to do something you've never done.

    Everyone should take the time to mark helpful posts and propose answers!

    Answer an interesting question?
    Create a wiki article about it!

    My Technet Wiki Articles



    Sunday, January 06, 2013 3:12 PM
  • Assigning events with AddHandler requires that the arguments of the sub you're attaching an event to has the parameters of the event. Timer.Tick has two parameters, the sender object, and the e eventargs. That's why when you double click a timer in the Designer, you get:

        Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
    
        End Sub

    BarStaticItem is not passed from the Timer.Tick event, which makes it throw an error.

    You could overcome it by, for example, making a custom class that holds a timer and an item.

    Here's an example, adding a new class MyTimer:

    Public Class MyTimer
        Public Tmr As Timer
        Public Item As BarStaticItem
    
        Sub New(tmr As Timer, item As BarStaticItem)
            Me.Tmr = tmr
            Me.Item = item
            AddHandler tmr.Tick, AddressOf Tmr_Tick
        End Sub
    
        Private Sub Tmr_Tick(sender As System.Object, e As System.EventArgs)
            Item.Appearance.BackColor = ColorTranslator.FromOle(14206908)
            Tmr.Stop()
        End Sub
    End Class
    

    This way you can create a new MyTimer like this:

        Public Sub GreenMessage(ByVal item As BarStaticItem, ByVal szoveg As String)
            item.Caption = szoveg
            item.ImageIndex = 2
            item.Appearance.BackColor = ColorTranslator.FromOle(greenstatusbar)
            My.Computer.Audio.Play(My.Resources.sapmsg, AudioPlayMode.Background)
            tmr.Interval = 500
            Dim tmrItem As New MyTimer(tmr, item)
            tmrItem.Tmr.Start()
        End Sub

    I hope you got it and that this helps.

    Sincerely yours,
    - bilde2910


    If a post is helpful to you or solves a problem, remember to mark it as answer, propose it as answer or vote up.
    Check out my development so far!

    • Proposed as answer by Heslacher Sunday, January 06, 2013 3:41 PM
    • Marked as answer by Mike FengModerator Thursday, January 10, 2013 9:50 AM
    Sunday, January 06, 2013 3:15 PM

All replies

  • You cannot add an event handler that does not have the correct matching signature for the event you are handling. A timer.Tick event does not have the following signature.
    ByVal item As BarStaticItem

    If you want something you've never had, you need to do something you've never done.

    Everyone should take the time to mark helpful posts and propose answers!

    Answer an interesting question?
    Create a wiki article about it!

    My Technet Wiki Articles



    Sunday, January 06, 2013 3:09 PM
  • I just want to clarify further, instead of trying to deviate from the intended signature of an event, instead try making your value public and accessing that value from there, meanwhile, you have to use a sub that has a matching signature of the event you are assigning to it.

    Public Class Form1
        Friend WithEvents Timer1 As New Timer
        Public Item As String
        Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
            AddHandler Timer1.Tick, AddressOf Timer1_Tick
        End Sub
        Sub Timer1_Tick(sender As Object, e As EventArgs)
    
        End Sub
    End Class


    If you want something you've never had, you need to do something you've never done.

    Everyone should take the time to mark helpful posts and propose answers!

    Answer an interesting question?
    Create a wiki article about it!

    My Technet Wiki Articles



    Sunday, January 06, 2013 3:12 PM
  • Assigning events with AddHandler requires that the arguments of the sub you're attaching an event to has the parameters of the event. Timer.Tick has two parameters, the sender object, and the e eventargs. That's why when you double click a timer in the Designer, you get:

        Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
    
        End Sub

    BarStaticItem is not passed from the Timer.Tick event, which makes it throw an error.

    You could overcome it by, for example, making a custom class that holds a timer and an item.

    Here's an example, adding a new class MyTimer:

    Public Class MyTimer
        Public Tmr As Timer
        Public Item As BarStaticItem
    
        Sub New(tmr As Timer, item As BarStaticItem)
            Me.Tmr = tmr
            Me.Item = item
            AddHandler tmr.Tick, AddressOf Tmr_Tick
        End Sub
    
        Private Sub Tmr_Tick(sender As System.Object, e As System.EventArgs)
            Item.Appearance.BackColor = ColorTranslator.FromOle(14206908)
            Tmr.Stop()
        End Sub
    End Class
    

    This way you can create a new MyTimer like this:

        Public Sub GreenMessage(ByVal item As BarStaticItem, ByVal szoveg As String)
            item.Caption = szoveg
            item.ImageIndex = 2
            item.Appearance.BackColor = ColorTranslator.FromOle(greenstatusbar)
            My.Computer.Audio.Play(My.Resources.sapmsg, AudioPlayMode.Background)
            tmr.Interval = 500
            Dim tmrItem As New MyTimer(tmr, item)
            tmrItem.Tmr.Start()
        End Sub

    I hope you got it and that this helps.

    Sincerely yours,
    - bilde2910


    If a post is helpful to you or solves a problem, remember to mark it as answer, propose it as answer or vote up.
    Check out my development so far!

    • Proposed as answer by Heslacher Sunday, January 06, 2013 3:41 PM
    • Marked as answer by Mike FengModerator Thursday, January 10, 2013 9:50 AM
    Sunday, January 06, 2013 3:15 PM
  • Use the Timer's Tag property to hold the item:

      Public Sub GreenMessage(ByVal item As BarStaticItemByVal szoveg As String)
        item.Caption = szoveg
        item.ImageIndex = 2
        item.Appearance.BackColor = 
    ColorTranslator.FromOle(greenstatusbar)
        
    My.Computer.Audio.Play(My.Resources.sapmsg, AudioPlayMode.Background)
        tmr.Tag = item
        tmr.Interval = 500
        
    AddHandler tmr.Tick, AddressOf tmr_tick()
        tmr.Start()
      
    End Sub
      
    Private Sub tmr_tick(sender As Object, e As EventArgs)
        
    Dim Item As BarStaticItem = DirectCast(tmr.Tag, BarStaticItem)
        item.Appearance.BackColor = 
    ColorTranslator.FromOle(14206908)
        tmr.Stop()
      
    End Sub

    Sunday, January 06, 2013 3:46 PM