Register service implementation in SimpleIOC in PCL

Question

I'm trying to register a service at the SimpleIOC that comes with MVVMLight. I have the ViewModelLocator in a PCL. I want to register a service from within my main project.

I'm working on Windows Phone 8.1 Silverlight and try to implement/register a navigation service.

public interface INavigationService
{
    void Navigate(string uri);
    void Navigate(string uri, Dictionary<string, string> parameters);
    void GoBack();
}

Implementation of my service interface:

public class NavigationService : INavigationService
{
    public NavigationService()
    {

    }

    public void Navigate(string uri)
    {
        DispatcherHelper.UIDispatcher.BeginInvoke(
            () => ((PhoneApplicationFrame)   Application.Current.RootVisual).Navigate(new Uri(uri, UriKind.Relative)));
    }

    public void Navigate(string uri, Dictionary<string, string> parameters)
    {
        throw new NotImplementedException();
    }

    public void GoBack()
    {
        DispatcherHelper.UIDispatcher.BeginInvoke(
            () => ((PhoneApplicationFrame) Application.Current.RootVisual).GoBack());
    }
}

This is how I register the service at the IOC container from within my App.xaml.cs (OnLaunching method)

// init the dispatcher helper for MVVM usage
DispatcherHelper.Initialize();

// add some platform specific services to the IOC container
SimpleIoc.Default.Register<INavigationService, NavigationService>();

And this is the error message that I can when starting my app:

Microsoft.Practices.ServiceLocation.ActivationException: Cannot register: No public constructor found in NavigationService.
at GalaSoft.MvvmLight.Ioc.SimpleIoc.GetConstructorInfo(Type serviceType)
at GalaSoft.MvvmLight.Ioc.SimpleIoc.Register[TInterface,TClass](Boolean createInstanceImmediately)
at GalaSoft.MvvmLight.Ioc.SimpleIoc.Register[TInterface,TClass]()
at TimeStamp.WindowsPhone.App.Application_Launching(Object sender, LaunchingEventArgs e)
at Microsoft.Phone.Shell.PhoneApplicationService.FireLaunching()
at Microsoft.Phone.TaskModel.Interop.Task.FireOnLaunching()

As I have a constructor in my NavigationService it seems that something obvious which I don't see is missing here.

Btw.: I want to use that service from within my main view model:

/// <summary>
/// Default constructor
/// </summary>
/// <param name="workDayServiceAgent"></param>
[PreferredConstructor]
public MainViewModel(IWorkDayServiceAgent workDayServiceAgent, INavigationService navigationService)
{
    // set the service agents
    _workDayServiceAgent = workDayServiceAgent;
    _navigationService = navigationService;
    ...

Answer 1

After more than two hours of more research in my code I figured out what the actual issue is. When registering NavigationService I'm actually not using my own implementation but System.Windows.Navigation.NavigationService. After renaming my NavigationService to NavigationServiceWP everything works fine.