Изображения/файлы не отображаются при упаковке моего приложения WINUI3

Позвольте мне показать вам пример, основанный на комментарии @Simon Mourier о Windows.Storage.ApplicationData.

В этом примере я добавил текстовый файл SomeText.txt в папку Assets в проекте.

MainPage.xaml

<Page
    x:Class = "WindowsStorageApplicationDataExample.MainPage"
    xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x = "http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d = "http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local = "using:WindowsStorageApplicationDataExample"
    xmlns:mc = "http://schemas.openxmlformats.org/markup-compatibility/2006"
    Background = "{ThemeResource ApplicationPageBackgroundThemeBrush}"
    mc:Ignorable = "d">

    <Grid RowDefinitions = "Auto,Auto,*">
        <Button
            Grid.Row = "0"
            Click = "InitializeButton_Click"
            Content = "Initialize" />
        <Button
            Grid.Row = "1"
            Click = "UpdateSomeTextButton_Click"
            Content = "Update SomeText.txt" />
        <ItemsRepeater
            Grid.Row = "2"
            ItemsSource = "{x:Bind Logs}" />
    </Grid>
</Page>

MainPage.xaml.cs

using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using System;
using System.Collections.ObjectModel;
using Windows.ApplicationModel;
using Windows.Storage;

namespace WindowsStorageApplicationDataExample;

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

    public ObservableCollection<string> Logs { get; } = new();

    private StorageFile? SomeTextInLocalStateFolderFile { get; set; }

    private async void InitializeButton_Click(object sender, RoutedEventArgs e)
    {
        StorageFolder installedLocationFolder = Package.Current.InstalledLocation;
        Logs.Add($"InstalledLocation: {installedLocationFolder.Path}");

        StorageFolder assetsFolder = await installedLocationFolder.GetFolderAsync("Assets");
        Logs.Add($"Assets folder: {assetsFolder.Path}");

        StorageFile someTextFile = await assetsFolder.GetFileAsync("SomeText.txt");
        Logs.Add($"SomeText.txt file: {someTextFile.Path}");

        StorageFolder localStateFolder = ApplicationData.Current.LocalFolder;
        Logs.Add($"LocalState folder: {localStateFolder.Path}");

        if (await localStateFolder.TryGetItemAsync("SomeText.txt") is StorageFile someTextInLocalStateFolderFile)
        {
            Logs.Add($"SomeText.txt file exists: {someTextInLocalStateFolderFile.Path}");
            SomeTextInLocalStateFolderFile = someTextInLocalStateFolderFile;
        }
        else
        {
            Logs.Add($"SomeText.txt file not found in {localStateFolder.Path}");
            SomeTextInLocalStateFolderFile = await someTextFile.CopyAsync(localStateFolder);
            Logs.Add($"SomeText.txt file created: {SomeTextInLocalStateFolderFile.Path}");
        }
    }

    private async void UpdateSomeTextButton_Click(object sender, RoutedEventArgs e)
    {
        if (SomeTextInLocalStateFolderFile is null)
        {
            Logs.Add("Not initialized.");
            return;
        }

        string someTextInLocalStateFolder = await FileIO.ReadTextAsync(SomeTextInLocalStateFolderFile);
        someTextInLocalStateFolder += Environment.NewLine + DateTime.Now;
        Logs.Add($"SomeText.txt in LocalStateFolder updated to: {someTextInLocalStateFolder}");
        await FileIO.WriteTextAsync(SomeTextInLocalStateFolderFile, someTextInLocalStateFolder);
    }
}