Solved

Empty placeholder to adjust for 1-based array.

Posted on 2006-07-13
2
1,377 Views
Last Modified: 2008-02-01
Hi Guys

I have the following problem with visual basic, this is not the actual code, but should illustrate the problem

I creates a new collection and a iterator, like

Dim collection as Collection
Dim it as Inode

then I create a node and inserts it into the collection, eg

collection.Add( new Inode , "key" )

then I would like to iterate through the collection, something like

For Each it in collection
   ....
next it

But I get an exception with the following message: {"Object reference not set to an instance of an object."}

My own explanation is like follows. When you call "Add" on the collection, a node is automatically generated that are a text string and inserted at the first position in the collection, then my node is added. When I iterate through the collection the first time I get the auto inserted string which cannot be casted to the type of my iterator and when I try to do a next, I get the exception, so basically my question is: Can you avoid to get the autoinserted node or can you avoid this node in your iteration.

Thanks, Niels





0
Comment
Question by:nielsboldt
2 Comments
 

Accepted Solution

by:
Coder1st earned 500 total points
ID: 17102067
Hi nielsboldt!

I tryed you code and the only thing that I see is that you need to change this line

Dim collection as Collection

to this

Dim [You Collection Name] as New Collection

and that should take care of that error.
0
 

Author Comment

by:nielsboldt
ID: 17106102
Hi

I found the cause of the error, and it was a really stupid mistake in the implementation of the enumerable interface.

Thanks for your time.
Niels
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Reading the Contents of a Directory In Access VBA 5 86
MS Access - Capture pressed key onclick 4 43
How to Add / Edit Windows Menu 4 73
Excel Automation VBA 19 102
I’ve seen a number of people looking for examples of how to access web services from VB6.  I’ve been using a test harness I built in VB6 (using many resources I found online) that I use for small projects to work out how to communicate with web serv…
Enums (shorthand for ‘enumerations’) are not often used by programmers but they can be quite valuable when they are.  What are they? An Enum is just a type of variable like a string or an Integer, but in this case one that you create that contains…
Get people started with the process of using Access VBA to control Outlook using automation, Microsoft Access can control other applications. An example is the ability to programmatically talk to Microsoft Outlook. Using automation, an Access applic…
Get people started with the utilization of class modules. Class modules can be a powerful tool in Microsoft Access. They allow you to create self-contained objects that encapsulate functionality. They can easily hide the complexity of a process from…

685 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question