Hi,
Anybody has experience to map ObservableCollection?

my code like this:


I tried all set, list, map, bag and arrary.
all of it cannot work.

exception is:

"Unable to cast object of type 'NHibernate.Collection.Generic.PersistentGenericBag`1[User]' to type 'System.Collections.ObjectModel.ObservableCollection`1[User]'."

Observable collections do not come packaged with NHibernate, so you will need to use a custom collection type. Gary DeReese has a workable example that accomplishes this, which he’s posted to his blog. I’ve recently been improving upon his work and submitting comments there. Go to Gary’s blog to get started: http://analog-man.blogspot.com/2007/01/ ... rnate.html

I’ve also started working on an "ObservableSet" class that derives from Iesi.Collections.Generic.HashedSet, which you may find useful.

Thank you HappyNomad.

It is working now.
I find that your post sample is a bit complicated.

I change my code to:



And in the mapping file, instead of mapping users collection, I map usersNhibernate property.

Are you sure that code behaves correctly? Every time NHibernate tries to set the usersNhibernate property to an instance of it's own collection implementation, it looks like your code then throws away that instance. You may find a problem after running some tests. Using the download from Gary's blog, I suggest you follow the example in ListContainer.cs. The collection property there gets set to an instance of either ObservableList<T> or PersistentGenericObservableBag<T>.

The code on Gary's blog is the best currently available for easily including persistent observable lists in your program. However, I've made a modified version which I think is an improvement. In my version, client collection properties are declared of type IList<T> and transient collection instances are of type ObservableCollection<T> instead of a custom collection class. This code is not yet online but I can let you know when it is.

I've completed my implementation of three types (bag, list, and set) of observable collections. See my blog entry (http://happynomad121.blogspot.com/2007/12/collections-for-wpf-and-nhibernate.html) for further details and to download the solution.