Avoid null field after storage in IsolatedStorageSettings

Question

On Silverlight, I got a DataContract like this:

[DataContract]
class Operation
{
    [DataMember]
    public string Name;

    public readonly OperationManager Manager = new OperationManager();
}

I do not want to store or serialize Manager, which is why it's not a DataMember. Manager is not-null when doing new Operation(). But when I retrieve it from IsolatedStorageSettings, I get a null Manager:

// operation.Manager is not null
var Settings = IsolatedStorageSettings.ApplicationSettings;
Settings["key"] = operation;
Settings.Save();
operation = (Operation)Settings["key"];
// operation.Manager is null

Is there a way to automatically re-initialize Manager to something new when it is being unserialized by IsolatedStorageSettings? I tried to set it in constructor, but constructor is not called when going through IsolatedStorageSettings.

Answer 1

The solution to initialize something coming from IsolatedStorageSettings is either [OnDeserializing] or [OnDeserialized] (can't use .ctor(SerializationInfo info, StreamingContext context) as not available on Silverlight).

[DataContract]
class Operation
{
    [DataMember]
    public string Name;

    OperationManager _manager = new OperationManager();
    public OperationManager Manager { get { return _manager; } }

    [OnDeserializing]
#if WP7
    internal
#endif
    void OnDeserializing(StreamingContext c)
    {
        _manager = new OperationManager();
    }
}

[OnDeserializing] and [OnDeserialized] must be internal on Windows Phone 7, and private on Visual Studio 2013. -_-