How to get the DisplayName of the package in C++/WinRT? - xaml

Question

i would like to get the DisplayName of the package in C++/WinRT.
As describe in this C# example:
<TextBlock x:Name="AppTitle"
Text="{x:Bind GetAppTitleFromSystem()}"
VerticalAlignment="Center"
Style="{StaticResource CaptionTextBlockStyle}" />
namespace AppUIBasics
{
public sealed partial class NavigationRootPage : Page
{
public string GetAppTitleFromSystem()
{
return Windows.ApplicationModel.Package.Current.DisplayName;
}
}
}
i tried to :
// .xaml.h file
struct MainWindow : MainWindowT<MainWindow>
{
MainWindow();
winrt::hstring GetAppTitleFromSystem();
}
...
// .xaml.cpp file
...
MainWindow::MainWindow()
{
InitializeComponent();
}
hstring MainWindow::GetAppTitleFromSystem()
{
Package package = Package::Current();
return package.DisplayName();
}
...
// .idl
namespace Example
{
[default_interface]
runtimeclass MainWindow : Microsoft.UI.Xaml.Window
{
MainWindow();
String GetAppTitleFromSystem{ get; };
}
}
i got error like:
2.Error XLS0525 Method 'GetAppTitleFromSystem' not found in type 'MainWindow. Example C:\Users\{..}\MainWindow.xaml 72