RaiseEvent not modifying ByRef argument as expected !

[Jaafar Tribak]

Hi Dear all.

Strictly speaking RaiseEvent is not a procedure but looks and does the same as one (ie: Executes code) . It also accepts arguments which can be passed ByVal or ByRef.

When an argument is passed ByRef to a Sub/Function , the procedure can modify the argument itself however this doesn't seem to be the case with RaiseEvent. Is this a known bug documented somewhere as i can't find a logic explanation to this problem.

Here is an example :

1-Class named (EventCls)

Event EventTest(ByRef Cancel As Boolean)

Public Sub RaiseEventTest()
 
    Dim Cancel As Boolean
    
    Cancel = False
    RaiseEvent EventTest(Cancel)
    MsgBox Cancel [COLOR=seagreen]'Should return TRUE as the Cancel arg is passed ByRef[/COLOR]
 
End Sub

2- Class named (EventHandlerCls)

Dim WithEvents EventHandler As EventCls

Private Sub EventHandler_EventTest(ByRef Cancel As Boolean)
 
    [COLOR=seagreen]'Modify argument[/COLOR]
    Cancel = True
 
End Sub

3- Bas Module (Caller)

Dim oEvent As EventCls

Sub Main()
 
    Set oEvent = New EventCls
    oEvent.RaiseEventTest
 
End Sub

Hope someone can give me some pointers.

Regards.

 

[dk]

Hi Jafaar

In your example I can't see a linkage between the EventCls module and the EventHandlerCls module. I reworked it like so and got the desired result (the argument passed by the event was changed). Make sense?

1. EventCls remains the same.

2. EventHandlerCls has this code:

Dim WithEvents EventHandler As EventCls

Sub CallRaiseEvent()

Set EventHandler = New EventCls

EventHandler.RaiseEventTest

End Sub

Private Sub EventHandler_EventTest(Cancel As Boolean)
Cancel = True
End Sub

3. Caller module has this

Sub Main()
 
    Dim Handler As EventHandlerCls
    
    Set Handler = New EventHandlerCls
    
    Handler.CallRaiseEvent
    
End Sub

DK

 

[Jaafar Tribak]

As you said no linkage . In fact i missed the obvious by not even creating an instance of the EventHandlerCls Class !

Thanks very much DK.