Xamarin Forms - My ContentPresenter won't show its Content - xaml

Question

I'm still getting used to Xamarin Forms, so I have the following control called PopupFrame:
PopupFrame.cs
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class PopupFrame : ContentView
{
public static readonly BindableProperty PopupContentProperty =
BindableProperty.Create(nameof(PopupContent), typeof(View), typeof(PopupFrame));
public View PopupContent
{
get { return (View)GetValue(PopupContentProperty); }
set { SetValue(PopupContentProperty, value); }
}
public PopupFrame()
{
InitializeComponent();
}
}
PopupFrame.xaml
<?xml version="1.0" encoding="UTF-8"?>
<ContentView xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="TestApp.Core.Controls.PopupFrame">
<Frame>
<StackLayout>
<Label Text="--- TEST TITLE ---" />
<ContentPresenter Content="{TemplateBinding PopupContent}" />
</StackLayout>
</Frame>
</ContentView>
In my view:
<popCtl:PopupFrame HorizontalOptions="Center"
VerticalOptions="Center">
<popCtl:PopupFrame.PopupContent>
<ListView x:Name="ListUsers">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<Label Text="{Binding Name}"
HorizontalOptions="CenterAndExpand"
VerticalOptions="Center" />
</ViewCell.View>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</popCtl:PopupFrame.PopupContent>
</popCtl:PopupFrame>
So what's happening is that When the ContentView control shows, only the Label (with the text -- TEST TITLE -- is displayed, but not the ListView).
I've also tried replacing the ContentPreseter with a ContentView, but same result: my ListView doesn't not show. And I made sure that data does in fact exist in the ItemsSource of the ListView (set in code-behind).
Is my ContentView setup wrong??

Answer 1

TemplateBinding can only be used to bind from inside a control-template. In order for your binding to work - you can use ReferenceExtension to refer to parent control.
For ex, update your binding as following:
<ContentView xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="TestApp.Core.Controls.PopupFrame"
x:Name="_parent">
<Frame>
<StackLayout>
<Label Text="--- TEST TITLE ---" />
<ContentPresenter
Content="{Binding Path=PopupContent, Source={x:Reference _parent}}" />
</StackLayout>
</Frame>
</ContentView>