Question

I have an object stored in a database that I am retrieving in my viewmodel and placing into an observable collection. These objects are properties (houses/realestate) that each have a child object called Images. Each property can have multiple images (but each image can only have one property). I only want to use one viewmodel. I have the properties populating a listbox fine, and I can successfully bind the images to a subsequent listbox, but only if I do it via iList. My question is how do I implement the Images into an observable collection of their own (so I can monitor changes), in place of the iList. Here is the code of some of the features I mentioned above…

        public IList<Image> Images
    {
        get
        {
            if (CurrentProperty != null)
                return CurrentProperty.Images.ToList();
            return null;
        }
    }

 private void Load()
    {
        PropertyList = new ObservableCollection<Property>(from property in entities.Properties.Include("Images") select property);        

        //Sort the list (based on previous session stored in database)
        var sortList = PropertyList.OrderBy(x => x.Sort).ToList();
        PropertyList.Clear();
        sortList.ForEach(PropertyList.Add);

        propertyView = CollectionViewSource.GetDefaultView(PropertyList);         
        if (propertyView != null) propertyView.CurrentChanged += new System.EventHandler(propertyView_CurrentChanged);           


        public const string PropertiesPropertyName = "PropertyList";
    private ObservableCollection<Property> _PropertyList = null;

    public ObservableCollection<Property> PropertyList
    {
        get
        {
            return _PropertyList;
        }

        set
        {
            if (_PropertyList == value)
            {
                return;
            }

            var oldValue = _PropertyList;
            _PropertyList = value;

            // Update bindings, no broadcast
            RaisePropertyChanged(PropertiesPropertyName);
        }
    }    

Answer 1

Ended up solving the issue by following the answer provided on this question:

Listview to display ObservableSelection

I created an observablecollection for the images and then created a new method images_Update() , which is called everytime the current item of the view (of the properties observable collection) changes. I also slotted it in at the bottom of the AddImage() and DeleteImage() method to ensure that when they are called the list is updated.