c# - 如何在我的服务中获取 IHostApplicationLifetime 并将其注入(inject)容器(控制台应用程序)

Question

关注此 answer ，我想注入(inject)IHostApplicationLifetime在我的类里面正确关机时方法StartAsync结束了。

但我不知道如何从控制台获取 applicationLifetime 并通过 de 内置的 dotnet core IoC 容器注入(inject)它:

public static IHostBuilder CreateHostBuilder(string[] args)
{
    return Host.CreateDefaultBuilder(args)
        .ConfigureAppConfiguration((hostingContext, config) =>
        {
            config.SetBasePath(Directory.GetCurrentDirectory())
            .AddCommandLine(args)
            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
        })
        .ConfigureServices((hostContext, services) =>
        {
            services.Configure<ConnectionStringConfiguration>(hostContext.Configuration.GetSection("ConnectionStrings"));
            services.AddTransient<ISmtpClient, MySmtpClient>();
            services.AddTransient<IEmailService, EmailService>();
            services.AddSingleton<IHostApplicationLifetime>(????); // What should I put here ????
            services.AddHostedService<EInvoiceSenderService>();
        })
        .UseSerilog();
}

谢谢 !

Answer 1

框架已经默认添加了它，因此您应该能够从托管服务作为注入(inject)依赖项访问它。
简化示例

public class EInvoiceSenderService: IHostedService {
    private readonly ILogger logger;
    private readonly IHostApplicationLifetime appLifetime;

    public EInvoiceSenderService(
        ILogger<LifetimeEventsHostedService> logger, 
        IHostApplicationLifetime appLifetime) { //<--- INJECTED DEPENDENCY
        this.logger = logger;
        this.appLifetime = appLifetime;
    }

    public Task StartAsync(CancellationToken cancellationToken) {
        appLifetime.ApplicationStarted.Register(OnStarted);
        appLifetime.ApplicationStopping.Register(OnStopping);
        appLifetime.ApplicationStopped.Register(OnStopped);

        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken cancellationToken) {
        return Task.CompletedTask;
    }


    private void OnStarted() {
        logger.LogInformation("OnStarted has been called.");

        // Perform post-startup activities here
    }

    private void OnStopping() {
        logger.LogInformation("OnStopping has been called.");

        // Perform on-stopping activities here
    }

    private void OnStopped() {
        logger.LogInformation("OnStopped has been called.");

        // Perform post-stopped activities here
    }    
}

引用: .NET Generic Host: IHostApplicationLifetime