Question

I have a WPF client application receiving objects via a reference to a remote WCF service. The WCF service references were generated via Visual Studio’s ‘Add Service Reference…’.

I would like to execute a piece of code each time an object received/deserialized from the WCF service. The object needs to already be deserialized so I can read properties/call methods on it. This solution would be global and not something I need to add to every WCF service call.

Answer 1

Starting with Mike’s initial response I was able to come up with the following solution.

Background

1. Client pulls data from the server, over a WCF service.
2. The WCF service reference is generated by Visual Studio with “reuse types in referenced assemblies” so no WCF proxy manipulation can be done.
3. A property on the Client side app needs to be modified when any property, on any of the objects received from WCF has changed (these objects implement INotifyPropertyChanged)

Forewarning

I understand that this breaks some object oriented and responsibility rules, however the solution is so short, so easy, and fits my current and anticipated future needs so it is what I went with. This solution is less practical when there is significant logic that needs to occur on each client-side deserialization.

[DataContract]
public class DataTransferObject : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    [OnDeserialized]
    public void OnDeserialized(StreamingContext context)
    {
        dynamic app = Application.Current;
        if(app != null) //Prevents execution on server-side.  This code is meant to only execute at the client
        {
            PropertyChanged += (sender, args) =>
                                   {
                                       app.IsAnythingDirty = true;
                                   };
        }
    }
}

The keys

1. The reason this works is the dynamic keyword. You have to use the
   dynamic keyword because the project containing the DTO cannot reference the
   UI project due to a circular reference. If it can’t reference the UI project the compiler does not know about the IsAnythingDirty boolean.
2. Checking whether Application.Current is null ensures that the code will only run on the client-side, not the server-side.