Question

I am having trouble with, as I said, setting a property’s property. Let’s say I have a class that represents a transaction. In my class I have a property that represents another class, such as this:

Public Class PersonRecord

    _myPerson = new Person()

    Public Property MyPerson as Person
    Get
        _myPerson = Person.GetAppropriatePerson(Me.PersonID)

        return _myPerson
    End Get

    Set
        _myPerson = value
    End Set
    End Property

So I essentially have a property that has a get filter that gets the appropriate person. The problem is that when I want to set the Person’s info through the property, VB seems to ignore that I even did it, such as this:

Me.myPersonRecord.Person.Name = "Some Name"

But when I put a watch on this, after setting the property, my value does not change. I am puzzled by this behavior. Is there something I’m doing wrong? Thanks!

Answer 1

Every time you do a get .MyPerson, the function Person.GetAppropriatePerson gets called.

I do not know the implementation of that function, but I would guess that it returns a new Person object every time that it is called.

You change the Name of one Person instance. The next time you call .MyPerson, another Person instance gets returned.

Depending on how this is supposed to work, you could do a few things, for instance:

• Call GetAppropriatePerson in the constructor (if personid is known at that time). Assign the return value to _myPerson, and make the MyPerson property read-only.
• Or initialize _myPerson to null, then in the MyPerson getter have a if _myPerson == null Then _myPerson = GetAppropriatePerson etc.