Complex Type Ignored by Entity Framework Code First?

It turns out that Entity Framework does not like the generic class EfObservableCollection.

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Building on Ladislav's answer to Entity Framework Code First and Collections of Primitive Types I'm attempting to create a wrapper type EfObservableCollection around an ObservableCollection that has an additional helper property to simplify persistence (certainly this solution has trade-offs, but it's seems workable for my domain). However, properties of type EfObservableCollection seem to be ignored by EF. No appropriate columns are created in the database.

Guessing that implementing IEnumerable might trigger EF to ignore that type, I commented out that implementation with no change in behavior. What am I missing here? Entity Class public class A { DataMember public long Id { get; set; } DataMember public string Text { get; set; } // Tags is not persisted DataMember public EfObservableCollection Tags { get; set; } } Wrapper Class ComplexType public class EfObservableCollection : IEnumerable { const string VALUE_SEPARATOR = "\x8"; // Backspace character.

Unlikely to be actually entered by a user. Assumes ASCII or UTF-8. Readonly string VALUE_SEPARATORS = new string { VALUE_SEPARATOR }; NotMapped protected ObservableCollection Collection { get; private set; } public EfObservableCollection() { Collection = new ObservableCollection(); } DataMember public string PersistHelper { get { string serializedValue = string.

Join(VALUE_SEPARATOR, Collection.ToArray()); return serializedValue; } set { Collection.Clear(); string serializedValues = value. Split(VALUE_SEPARATORS, StringSplitOptions. None); foreach (string serializedValue in serializedValues) { Collection.

Add((T)Convert. ChangeType(serializedValue, typeof(T))); // T must implement IConvertable, else a runtime exception. } } } public void Add(T item) { Collection.

Add(item); } IEnumerator GetEnumerator() { return Collection.GetEnumerator(); } System.Collections. IEnumerator System.Collections.IEnumerable.GetEnumerator() { return GetEnumerator(); } } entity-framework-4 ef-code-first link|improve this question asked Dec 1 '11 at 23:10Eric J.24.6k22873 92% accept rate.

It turns out that Entity Framework does not like the generic class EfObservableCollection. If I derive a non-generic class from that class, data is persisted as expected: ComplexType public class EfObservableCollectionString : EfObservableCollection { }.

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