WPF-Demo/Waaagh/Program.cs

using System.Windows;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Waaagh.Models;
using Waaagh.Services.Abstract;
using Waaagh.ViewModels;
using Waaagh.Views;

namespace Waaagh {
    public class Program {
        [STAThread]
        static public void Main(string[] args) {
            SQLitePCL.Batteries.Init();

            IHost host = CreateHostBuilder(args).Build();
            host.Start();

            Application application = host.Services.GetRequiredService<Application>();

#if DEBUG
            //  DbTest(host);
#endif

            application.Run();
        }

        static private IHostBuilder CreateHostBuilder(string[] args) {
            return Host.CreateDefaultBuilder(args)
                .ConfigureServices(services => {
                    services.AddDbContextFactory<AppDatabaseContext>((sp, options) => {
                        IConfiguration configuration = sp.GetRequiredService<IConfiguration>();
                        string? sqliteConnectionString = configuration.GetConnectionString("Default");
                        if (string.IsNullOrWhiteSpace(sqliteConnectionString)) {
                            throw new Exception("Configuration Database Connection String Error.");
                        }
                        options.UseSqlite(sqliteConnectionString);
                    });
                })
                .AddDefaultMessageManager()
                .AddDefaultMessageCatcher()
                .AddDefaultScenarioManager()
                .ConfigureServices(services => {
                    // MainWindow
                    services.AddSingleton<MainViewModel>();
                    services.AddSingleton<MainWindow>(sp => {
                        return new MainWindow() {
                            DataContext = sp.GetRequiredService<MainViewModel>()
                        };
                    });
                })
                .ConfigureServices(services => {
                    // Application
                    services.AddSingleton<Application>(sp => {
                        Application application = new Application() {
                            MainWindow = sp.GetRequiredService<MainWindow>(),
                        };
                        application.Startup += (s, e) => {
                            if (s is Application application) {
                                application.MainWindow.Show();
                            }
                        };
                        return application;
                    });
                });
        }

        static public void DbTest(IHost host) {
            IDbContextFactory<AppDatabaseContext> factory = host.Services.GetRequiredService<IDbContextFactory<AppDatabaseContext>>();
            AppDatabaseContext context = factory.CreateDbContext();
            {
                Scenario scenario = new Scenario() {
                    Id = 1,
                    Name = "Test"
                };
                if (context.Scenarios.Contains(scenario) == false) {
                    context.Scenarios.Add(scenario);

                }
                else {
                    scenario.IsLegacy = true;
                    context.Scenarios.Update(scenario);
                }
                context.SaveChanges();
            }
            foreach (Scenario scenario in context.Scenarios) {
                Console.WriteLine($"{scenario.Name}-{scenario.Id}<{scenario.IsLegacy}>: {scenario.Description}.");
            }
        }
    }
}