How to add UWP to an existing Xamarin.Forms project
1.Click on the Solution and add a new UWP project.
2.Add to the UWP project this NuGet packaget: Xamarin.Forms.
3.Click on the Reference in the Portable project and add as reference your UWP project.
4.Go to the UWP project and open the APP.xaml.cs file and add this line:
// under this line
rootFrame.NavigationFailed += OnNavigationFailed;
// add this line
Xamarin.Forms.Forms.Init (e); // requires the `e` parameter
5. From the MainPage.xaml delete the contant of this element <Page> (just a Grid)
Add this:
xmlns:forms=”using:Xamarin.Forms.Platform.UWP”
6 . Change the <Page to <forms:WindowsPage
<forms:WindowsPage
…
xmlns:forms=”using:Xamarin.Forms.Platform.UWP”
…
</forms:WindowsPage>
7 . Open the MainPage.xaml.cs and delete this “: Page” after MainPage class name.
8 . Add this lane:
// after this line
this.InitializeComponent();
// add this line
LoadApplication(new YOUR_NAMESPACE.App());