我应该如何在WinUI3应用程序中实现依赖项注入?

在WinUI3应用程序中有多种实现依赖项注入的方法,我看不出其中的区别。

例如,它们之间有什么区别?

首次实施:

IConfiguration configuration = new ConfigurationBuilder()
    .AddJsonFile("appsettings.json", true, true)
    .Build();

var services = new ServiceCollection();

services.AddSingleton<IExempleService, ExempleService>();
services.AddSingleton<MainWindow>();

services.AddDbContext<MyContext>(
    options =>
    {
        options.UseSqlServer(configuration.GetConnectionString("DefaultConnection"));
    },
    ServiceLifetime.Scoped
);

services.BuildServiceProvider();

第二次实施:

Host = Microsoft.Extensions.Hosting.Host.
CreateDefaultBuilder().
UseContentRoot(AppContext.BaseDirectory).
ConfigureServices((context, services) =>
{
    services.AddSingleton<IExempleService, ExempleService>();

    services.AddDbContext<MyContext>(options =>
        options.UseSqlServer(context.Configuration.GetConnectionString("DefaultConnection"))
    );
}).
Build();