Collection Of Object's To Store/retrieve The Data

I like the PHP way of doing things but, it seems I am stuck with using a Collection of Object's to store/retrieve the data I need. I have my Collection loaded with my Objects's and the code to iterate through the collection, my problem is I am unable to retrieve the "key" as it would be called in PHP (I believe in this case it is actually the name of the object).

Consider the following example:

Dim xDoc As XPathDocument = New XPathDocument(fName)
Dim xNav As XPathNavigator = xDoc.CreateNavigator()

Dim sender As XPathNodeIterator

[CODE]...

As you can see, I am navigating an XML document, and creating an Object with some Key/Value pairs. The Object would look something like this if it were in JSON:

{"name":"John Smith","address1":"123 Anywhere St.","city":"This City","state":"FL"}

When I iterate though the Collection I can only get the value of the object, but I need the Key, in this instance I want "name","address1","city","state" to be stored in a variable for each iteration.