Daniel Hindrikes

Xamarin has finally released support for Windows apps using WinRT. This make it possible to write apps for Windows Phone 8.1 (the stable release uses Windows Phone 8 Silverlight but can be upgraded to Windows Phone 8.1 Silverlight by changing target platform) and Windows 8.1. It's still in preview and Xamarin not recommending that we uses it for production apps yet. This post will show you how to add Windows apps to your existing Xamarin.Forms project.

First thing to do is to make sure that you have the correct PCL profile for your shared Xamarin.Forms project. If you have created your project from Xamarin.Forms PCL template you have to check Windows Phone 8.1.

Next step is to create a Blank Windows App.

When you have done that you have to add the nuget package for Xamarin.Forms to the Windows project.

Run Install-Package Xamarin.Forms.Windows -Pre in the "Package Manager Console".

When the package is installed open up MainPage.xaml and add the Xamarin.Forms namespace and change Page to forms:WindowsPage.

You also have to remove that MainPage is inherits from Page in MainPage.xaml.cs. To start the forms application run LoadApplication with the App class from the shared project as an argument.

 public sealed partial class MainPage
    {
        public MainPage()
        {
            this.InitializeComponent();

            LoadApplication(new MyApp.App());
        }
    }

The last step is to call the Xamarin.Forms Init method (Xamarin.Forms.Forms.Init(e);) in App.xaml.cs. The call should be in the OnLaunched method after before if (e.PreviousExecutionState == ApplicationExecutionState.Terminated). It will be around line 65.

if (rootFrame == null)
            {
                // Create a Frame to act as the navigation context and navigate to the first page
                rootFrame = new Frame();
                // Set the default language
                rootFrame.Language = Windows.Globalization.ApplicationLanguages.Languages[0];

                rootFrame.NavigationFailed += OnNavigationFailed;

                Xamarin.Forms.Forms.Init(e);

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    //TODO: Load state from previously suspended application
                }

                // Place the frame in the current Window
                Window.Current.Content = rootFrame;

If you want to use Xamarin.Forms for a Windows Phone 8.1 (with WinRT) app follow the same steps, for a Windows Phone 8.1 project.