How to use TabbedPage in Xamarin WPF - wpf

Question

I am trying to rebuild my old WinForms application using Xamarin Forms for more portability.
The application uses a TabControl, and the docs say that the closest Xamarin Forms element is the TabbedPage.
Here is the code:
<?xml version="1.0" encoding="utf-8" ?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:MyApp"
x:Class="MyApp.MainPage">
<TabbedPage.ToolbarItems>
<ToolbarItem Text="Settings"
Order="Primary"
Priority="0" />
<ToolbarItem Text="Tools"
Order="Primary"
Priority="1" />
<ToolbarItem Text="Help"
Order="Primary"
Priority="2" />
</TabbedPage.ToolbarItems>
<TabbedPage.Children>
<ContentPage Title="Main">
<Label Text="Coming soon!"/>
</ContentPage>
<ContentPage Title="Today">
<Label Text="Coming soon!"/>
</ContentPage>
<ContentPage Title="This week">
<Label Text="Coming soon!"/>
</ContentPage>
</TabbedPage.Children>
</TabbedPage>
It works well on my UWP build:
However, on my WPF build, it does not show the toolbar, making it impossible to switch tabs:
So what am I doing wrong here?
Thanks.
Update #1: I've tried to build the GTK target, it works correctly:
This screenshot is taken on Ubuntu. GTK# on Windows works the same way, but the drawing of the controls are too buggy.

Answer 1

After messing up with the element picker in the toolbar, I've finally found an answer:
There ARE buttons to switch between tabs in WPF. However, they are just invisible:
Setting the BarTextColor property in TabbedPage fixes the problem:
So the resulting code is:
<?xml version="1.0" encoding="utf-8" ?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:TimetableApp"
x:Class="TimetableApp.MainPage"
BarTextColor="Black">
<TabbedPage.ToolbarItems>
<ToolbarItem Text="Settings"
Order="Primary"
Priority="0" />
<ToolbarItem Text="Tools"
Order="Primary"
Priority="1" />
<ToolbarItem Text="Help"
Order="Primary"
Priority="2" />
</TabbedPage.ToolbarItems>
<TabbedPage.Children>
<ContentPage Title="Main">
<Label Text="Coming soon!"/>
</ContentPage>
<ContentPage Title="Today">
<Label Text="Coming soon!"/>
</ContentPage>
<ContentPage Title="This week">
<Label Text="Coming soon!"/>
</ContentPage>
</TabbedPage.Children>
</TabbedPage>