ASP.NET COM+ Dispose Exception

Question

our ASP.NET application is using COM+ to connect to Database

we have this structure:

1. A Base Class :

   Imports System.EnterpriseServices

   Public Class Base Inherits ServicedComponent

2. A Child Class:

    Public Class Member Inherits Base
   

   'Propreties . . .

   'Methods
   Public Sub SetMember(ByVal SelectedQueue As String)
           ...
   End Sub
   

In a Aspx page, we search for a member and set details:

Dim newMember As Member =  New Member 
newMember.SetMember(MemberNumber)
Session("SelectedMember") = newMember

We then dispose newMember:

 If Not newMember Is Nothing Then
                newMember.Dispose()
 End If

but whenver we access the session we got an exception:

   If Not Session("SelectedMember") Is Nothing Then
                'Something
            Else
                'Something else
            End If 

the exception is : Cannot access a disposed object. Object name: 'ServicedComponent'.

How can I dispose the object but keep my session valid?

Answer 1

I can see what you're doing wrong, but can't be clear on what would be right. Your logic as stated is:

1. Obtain object.
2. Store object.
3. Clean-up object, rendering it useless.
4. Retrieve object.
5. Use object.

Having 3 before 5 makes no sense.

If the object is quick to obtain, you should just do so on every page. (Often people over-estimate the cost of this).

If the object is slow to obtain, and it makes sense to store for a long term, then it shouldn't need to be cleaned-up. What is Dispose() actually doing here? With it obtaining and releasing resources used by members as needed.

I suspect that the first is the one to go for here, but that's mostly a guess.

I'd also be concerned when you talk about the database, does your object hold a database connection? If so, and pooling is available, then you should be releasing those connections as fast as possible, rather than holding onto them.