Problem with converting "eventhandlers" from c# to vb.net

• • Reply

  13 years ago

  by sarakkkk

  sara kamal

  , Jordan

  Joined 13 years ago

  Hi all
  i have trouble with converting some pices of my old c# code to vb.net and hope someone here can help me.

  Code :

  Public NotInheritable Class ......

   Public Shared Event ResolvingServiceProvider As EventHandler(Of ResolvingServiceProviderEventArgs)
   ....
   ....
   
   Public Shared Function CreateProvider(ByVal providerType As Type) As IServiceProvider
   
    Dim provider As IServiceProvider = CreateFromType(providerType)
    
    ' working c# code
    'if (ResolvingServiceProvider != null)
    '{
    'ResolvingServiceProviderEventArgs e = new ResolvingServiceProviderEventArgs(provider, null);
    'ResolvingServiceProvider(null, e);
    'provider = e.ServiceProvider;
    '}  

    ' New VB.Net code (2005)
    If ResolvingServiceProvider IsNot Nothing Then   ' Error (*)

     Dim e As New ResolvingServiceProviderEventArgs(provider, Nothing)
     RaiseEvent ResolvingServiceProvider(Nothing, e) ' Working
     provider = e.ServiceProvider
    End If

    ... 

              Return provider
      
          End Function

   ...
   
  End Class 

   (*)  ' Error (Fehler 4 "Public Shared Event ResolvingServiceProvider(sender As Object, e As ResolvingServiceProviderEventArgs)" ist ein Ereignis und kann nicht direkt aufgerufen werden. Verwenden Sie eine RaiseEvent-Anweisung, um ein Ereignis aufzurufen.)

   I tryed to use the RaiseEvent also for the if statement but this dont work too

  PS : Excuses my bad English. My school time is past already 30 years ;-)

   

  Report abuse
• • Reply

  13 years ago

  by Mulish Mehdi

  Tehran, Iran

  Joined 16 years ago

  Hi there,

  I'm sorry, I can't  understand your question. Do you want to create an custom event in VB.NET? if it's true, see the following code:

      Public ResolvingServiceProviderHandler As EventHandler
  
      Public Custom Event ResolvingServiceProvider As EventHandler
          AddHandler(ByVal value As EventHandler)
              ResolvingServiceProviderHandler = value
          End AddHandler
          RemoveHandler(ByVal value As EventHandler)
              ResolvingServiceProviderHandler = Nothing
          End RemoveHandler
          RaiseEvent(ByVal sender As Object, ByVal e As System.EventArgs)
              ResolvingServiceProviderHandler.Invoke(sender, e)
          End RaiseEvent
      End Event
  
      Public Overridable Sub OnResolvingServiceProvider(ByVal e As EventArgs)
          If (ResolvingServiceProviderHandler IsNot Nothing) Then
              RaiseEvent ResolvingServiceProvider(Me, e)
          End If
      End Sub

  Report abuse
• • Reply

  13 years ago

  by jmcilhinney

  John McIlhinney

  Sydney, Australia

  Joined 15 years ago
  You just use the RaiseEvent statement.  You don't test the event itself to see whether it has any handlers registered as that's not supports in VB.
  
  Report abuse