Question

There is a WCF service:

    public List<Aktivy> Aktivy()
    {
        DataClassesDataContext db = new DataClassesDataContext();
        var aktivy = from akt in db.Aktivys
                     select aktivy;
        return aktivy.ToList();
    }

Also there is a Silverlight client that accesses the WCF service:

    private void Grid_Loaded(object sender, System.Windows.RoutedEventArgs e)
    {
        ServiceReference.ServiceClient webService = new ServiceReference.ServiceClient();
        webService.AktivyCompleted += new EventHandler<ServiceReference.AktivyCompletedEventArgs>(webService_AktivyCompleted);
        webService.AktivyAsync();
    }

    void webService_AktivyCompleted(object sender, ServiceReference.AktivyCompletedEventArgs e)
    {            

    }

How to convert e.Result (which features webService_AktivyCompleted) in the List<Aktivy> on the client side?

Answer 1

By default when you configure a service reference in Silverlight the collection types are set to deserialise into ObservableCollection<T> (which is not a List<T>). If you always want a simple List<T> you can modify the configuration of the service reference (right mouse on the service in Solution Explorer) and set collections to be represented as List<T>.

However a better approach when dealing with these things is to work with interfaces instead of demanding a specific type. Modify your code to work with IList<T> (a ObservableCollection<T> implements IList<T>) instead of List<T>, this will work with any of the possible collection types that a service may be configured for.

Since ObservableCollection<T> is the most versatile of the available choices you would have to have a good reason why the collection must be List<T>. One reason might be because you are sharing code between server and client.