c# - 如何使用 BackgroundService 和依赖注入(inject)运行 Winforms？

Question

我正在尝试启动分配给 IHostBuilder 的 services.HostedService 的 BackgroundService。

IHostBuilder定义:

private static IHostBuilder CreateHostBuilder()
    {
        return Host.CreateDefaultBuilder()
            .ConfigureServices(services =>
            {
                services.AddHostedService<LicenseControl>();

                services.AddTransient<Database>();
                services.AddTransient<CoreLicense>();

                services.AddSingleton<FormSelector>();

                services.AddTransient<ClienteForm>();
                services.AddTransient<GastoForm>();
                services.AddTransient<IngredienteForm>();
                services.AddTransient<ProdutoForm>();
                services.AddTransient<ReceitaForm>();
                services.AddTransient<RelatorioForm>();
                services.AddTransient<VendaForm>();
                services.AddTransient<MainForm>();
                services.AddTransient<ConfiguracoesForm>();
                services.AddTransient<UsuarioForm>();

                services.AddSingleton<AuthenticationForm>();
                
                services.AddScoped<IBridgeRepository, BridgeRepository>();
                services.AddScoped<IClienteRepository, ClienteRepository>();
                services.AddScoped<IGastoRepository, GastoRepository>();
                services.AddScoped<IIBGERepository, IBGERepository>();
                services.AddScoped<IIngredienteRepository, IngredienteRepository>();
                services.AddScoped<IProdutoRepository, ProdutoRepository>();
                services.AddScoped<IReceitaRepository, ReceitaRepository>();
                services.AddScoped<IVendaRepository, VendaRepository>();
                services.AddScoped<IUsuarioRepository, UsuarioRepository>();

                services.AddLogging(
                builder =>
                {
                    builder.AddFilter("Microsoft", LogLevel.Warning)
                           .AddFilter("System", LogLevel.Warning)
                           .AddFilter("NToastNotify", LogLevel.Warning)
                           .AddConsole();
                }
                );
            });
    }

但我发现启动 HostedService 的唯一可能方法是运行以下命令:

await CreateHostBuilder().Build().RunAsync();   

最后，问题发生了，因为在这种方法中，线程锁定在那一行并且不让我运行公共(public) block 代码来启动 Form 本身:

Application.Run(new MainForm());

如果我先运行 Form，也会发生同样的情况，该行上的线程锁定并且不允许我调用 HostBuilder< 的 RunAsync/strong>.

我还尝试在 Form 类上声明所有 HostBuilder 范围，并在其构造函数上启动 BackgroundService，但之后我将无法运行 Async 方法在 Actor 身上。

我目前正在尝试(但还没有成功)是在没有 Application.Run 的情况下调用 Form(并且仍然不知道所有的副作用通过这样做)，所以我接下来可以运行 HostBuilder。

现在我的整个程序类:

static class Program
{
    [STAThread]
    private static async Task Main()
    {
        Application.SetHighDpiMode(HighDpiMode.SystemAware);
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);            

        var host = CreateHostBuilder().Build();

        host.Services.GetRequiredService<AuthenticationForm>().Show();

        await host.RunAsync();
    }
    private static IHostBuilder CreateHostBuilder()
    {
        return Host.CreateDefaultBuilder()
            .ConfigureServices(services =>
            {
                services.AddHostedService<LicenseControl>();

                services.AddTransient<Database>();
                services.AddTransient<CoreLicense>();

                services.AddSingleton<FormSelector>();

                services.AddTransient<ClienteForm>();
                services.AddTransient<GastoForm>();
                services.AddTransient<IngredienteForm>();
                services.AddTransient<ProdutoForm>();
                services.AddTransient<ReceitaForm>();
                services.AddTransient<RelatorioForm>();
                services.AddTransient<VendaForm>();
                services.AddTransient<MainForm>();
                services.AddTransient<ConfiguracoesForm>();
                services.AddTransient<UsuarioForm>();

                services.AddSingleton<AuthenticationForm>();
                
                services.AddScoped<IBridgeRepository, BridgeRepository>();
                services.AddScoped<IClienteRepository, ClienteRepository>();
                services.AddScoped<IGastoRepository, GastoRepository>();
                services.AddScoped<IIBGERepository, IBGERepository>();
                services.AddScoped<IIngredienteRepository, IngredienteRepository>();
                services.AddScoped<IProdutoRepository, ProdutoRepository>();
                services.AddScoped<IReceitaRepository, ReceitaRepository>();
                services.AddScoped<IVendaRepository, VendaRepository>();
                services.AddScoped<IUsuarioRepository, UsuarioRepository>();

                services.AddLogging(
                builder =>
                {
                    builder.AddFilter("Microsoft", LogLevel.Warning)
                           .AddFilter("System", LogLevel.Warning)
                           .AddFilter("NToastNotify", LogLevel.Warning)
                           .AddConsole();
                }
                );
            });
    }
}

考虑到 .NET 5 并忽略 BackgroundWorker 组件，有什么解决方法？

Answer 1

Nkosi 的解决方案，评论:

Make another hosted service to invoke Application.Run that way when you run the host, the UI aspect and background worker hosted services will be started

class StartProgram : BackgroundService
{
    private readonly IServiceProvider _services;
    public StartProgram(IServiceProvider services)
    {
        this._services = services;
    }
    protected override Task ExecuteAsync(CancellationToken stoppingToken)
    {
        Application.SetHighDpiMode(HighDpiMode.SystemAware);
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run((AuthenticationForm)_services.GetService(typeof(AuthenticationForm)));

        return Task.CompletedTask;
    }
}

和 Program.cs:

static class Program
{
    [STAThread]
    private static async Task Main()
    {
        await CreateHostBuilder().Build().RunAsync();
    }
    private static IHostBuilder CreateHostBuilder()
    {
        return Host.CreateDefaultBuilder()
            .ConfigureServices(services =>
            {
                services.AddHostedService<LicenseControl>();
                services.AddHostedService<StartProgram>();

                #region ETC...
            });
    }
}