StackNavigation-Setup.md

Getting started with Stack Navigation

1. Install the latest version of Chinook.StackNavigation.Uno.WinUI in your project.

2. Create a base class that implements INavigableViewModel for your ViewModels.

   You can use the MVVM framework of your choice. In this sample, we use ViewModelBase from Chinook.DynamicMvvm.

   using Chinook.DynamicMvvm;
   using Chinook.StackNavigation;
   using Windows.UI.Xaml.Controls;
   namespace ChinookSample
   {
     public class ViewModel : ViewModelBase, INavigableViewModel
     {
       public void SetView(object view)
       {
         // For Chinook.DynamicMvvm, we want to create an MVVM dispatcher using the CoreDispatcher of the Page.
         Dispatcher = new CoreDispatcherDispatcher((Page)view);
       }
     }
   }

3. Map your ViewModels to Pages.

   Create a method returning a dictionary associating the types. You can put that method in App.xaml.cs.

   private static IReadOnlyDictionary<Type, Type> GetPageRegistrations() => new Dictionary<Type, Type>()
   {
     // Assuming that MainPageViewModel is a class that inherits from the ViewModel class of the previous step.
     { typeof(MainPageViewModel), typeof(MainPage) }
   };

4. From a blank WinUI application, create a FrameStackNavigator using the predefined rootFrame in the OnLaunched method of App.xaml.cs.

   Overral, OnLaunched should look like this after the changes.

   protected override void OnLaunched(LaunchActivatedEventArgs e)
   {
      Frame rootFrame = Window.Current.Content as Frame;
      IStackNavigator navigator = null;
   
      // Do not repeat app initialization when the Window already has content,
      // just ensure that the window is active
      if (rootFrame == null)
      {
         // Create a Frame to act as the navigation context and navigate to the first page
         rootFrame = new Frame();
         rootFrame.NavigationFailed += OnNavigationFailed;
   
         navigator = new FrameStackNavigator(rootFrame, GetPageRegistrations());
   
         if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
         {
    		//TODO: Load state from previously suspended application
         }
   
    	// Place the frame in the current Window
         Window.Current.Content = rootFrame;
      }
   
      if (e.PrelaunchActivated == false)
      {
         if (rootFrame.Content == null)
         {
    		// When the navigation stack isn't restored navigate to the first page,
    		// configuring the new page by passing required information as a navigation
    		// parameter
    		navigator.Navigate(CancellationToken.None, () => new MainPageViewModel());
         }
         // Ensure the current window is active
         Window.Current.Activate();
      }
   }

5. Start your application!

   From there you probably want to publicly expose the your IStackNavigator instance to your ViewModels so that they can manipulate the navigation. You can do that using the pattern of your choice.