byref variables in ActiveX component events

byref variables in ActiveX component events

I am creating an ActiveX DLL and I want to be able to fire events that can be cancelled similiarly to cancelling the Unload event for a form. however, I notice that even though an argument (passed byRef) can be included in the event declaration, there is not an explicit way to reference the argument in the ActiveX component after the event has fired?to then process the Cancel argument. See the included code:

ActiveX component codeOption ExplicitPublic Event WillFire(Cancel As Boolean)Public Sub myMethod(Cancel As Boolean)    RaiseEvent WillFire(False)    MsgBox "Event has Fired"End SubClient codeOption ExplicitPrivate WithEvents myObject As CObjectPrivate Sub btnExample_Click()    Set myObject = New CObject    myObject.myMethod FalseEnd SubPrivate Sub myObject_MethodHasFired()    MsgBox "Object Event has Fired"End SubPrivate Sub myObject_MethodWillFire(Cancel As Boolean)    'if some condition exists then        ' set cancel flag for the object method        Cancel = True    'endifEnd Sub

My question is: How can I include a byRef argument in my Event Declaration and evaluate that same argument in the ActiveX component once the event has fired?

You must pass a ByRef variable when you raise the event, because that is the variable that is passed to the client’s event procedure:

Public Event WillFire(Cancel As Boolean)Public Sub myMethod()Dim b as boolean    RaiseEvent WillFire(b)	If b=true then	    MsgBox "Event has not Fired"	Else	    MsgBox "Event has Fired"	End IfEnd Sub

Try enclosing the b variable in two sets of parenthesis, ((b)), this passes the variable ByVal.

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