The INavigationService allows a developer to navigate to other pages inside an application using view models only.

All pages will have to be registered manually or following the right naming convention.

For WPF and Silverlight, the pages must inherit from Page. For WP7, the pages must inherit from PhoneApplicationPage. In WPF, the parameters are of type Dictionary<string, object>, in Silverlight and WP7, the arguments are of type Dictionary<string, string>.

Closing an application

It is possible to close an application using the following code:

var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.CloseApplication();

Preventing an application to be closed

To prevent an application to be closed, one can subscribe to the ApplicationClosing event:

var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.ApplicationClosing += (sender, e) 
=>
{
   e.Cancel = true;
};

Navigating to a new view

To navigate to a new page, use the following code:

var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.Navigate<EmployeeViewModel>();

Navigating with parameters

It is very easy to navigate to a new page with parameters. Use the following code:

var parameters = new Dictionary<string, object>();
parameters.Add("id", employee.EmployeeID);
 
var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.Navigate<EmployeeViewModel>(parameters);

To read the navigation parameters in the receiving view model, use the OnNavigationCompleted method.

Navigating back and forward

The service also supports navigating back and forward:

var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.GoBack(); // navigates to the previous page, obviously
navigationService.GoForward(); // navigates to the next page, obviously

Navigating to a custom Uri

To navigate to a custom uri without a view model type, use the following code. Of course it's also possible to pass parameters using the right method overload.

var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.Navigate("/UI/Pages/EmployeePage.xaml");

Registering custom views

To register custom views, use the following code:

var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.Register(typeof(EmployeeViewModel), typeof(EmployeeDetailsPage));

Using naming conventions to find pages

If you use a consistent naming convention for views, it is possible to apply this naming convention to the service. This saves a lot of custom registration. When a page is not registered, the Show method will try to find the view using the naming convention.

To add a naming convention, use the following code:

var dependencyResolver = this.GetDependencyResolver();
var navigationService = dependencyResolver.Resolve<INavigationService>();
navigationService.NamingConventions.Add(string.Format("/Views/My{0}View", NamingConvention.ViewModelName));

The above naming convention will use the following combination:

Input: MyAssembly.UI.ViewModels.EmployeeViewModel

Output: MyAssembly.UI.Windows.EmployeeWindow

By default, the following naming conventions will be used:

/Views/[VM].xaml
/Views/[VM]View.xaml
/Views/[VM]Control.xaml
/Views/[VM]Page.xaml
/Views/[VM]Window.xaml
/Controls/[VM].xaml
/Controls/[VM]Control.xaml
/Pages/[VM].xaml
/Pages/[VM]Page.xaml
/Windows/[VM].xaml
/Windows/[VM]Window.xaml
/UI/Views/[VM].xaml
/UI/Views/[VM]View.xaml
/UI/Views/[VM]Control.xaml
/UI/Views/[VM]Page.xaml
/UI/Views/[VM]Window.xaml
/UI/Controls/[VM].xaml
/UI/Controls/[VM]Control.xaml
/UI/Pages/[VM].xaml
/UI/Pages/[VM]Page.xaml
/UI/Windows/[VM].xaml
/UI/Windows/[VM]Window.xaml