.NET Core 2.0 引入了 IHostedService ,基于它可以很方便地执行后台任务,.NET Core 2.1 则锦上添花地提供了 IHostedService 的默认实现基类 BackgroundService ,在这篇随笔中分别用 Web 与 Console 程序体验一下。
首先继承 BackgroundService 实现一个 TimedBackgroundService
public class TimedBackgroundService : BackgroundService { private readonly ILogger _logger; private Timer _timer; public TimedBackgroundService(ILogger<TimedBackgroundService> logger) { _logger = logger; } protected override Task ExecuteAsync(CancellationToken stoppingToken) { _timer = new Timer(DoWork, null, TimeSpan.Zero, TimeSpan.FromSeconds(5)); return Task.CompletedTask; } private void DoWork(object state) { _logger.LogInformation($"Hello World! - {DateTime.Now}"); } public override void Dispose() { base.Dispose(); _timer?.Dispose(); } }
在 ASP.NET Core Web 程序中执行这个后台定时任务只需在 Startup 的 ConfigureServices 注册 TimedBackgroundService 即可:
public void ConfigureServices(IServiceCollection services) { services.AddHostedService<TimedBackgroundService>(); }
然后只要站点启动,就会定时输出日志:
Now listening on: http://localhost:5000 Application started. Press Ctrl+C to shut down. info: BackgroundServiceSample.Services.TimedBackgroundService[0] Hello World! - 9/14/2018 17:48:02 info: BackgroundServiceSample.Services.TimedBackgroundService[0] Hello World! - 9/14/2018 17:48:07 info: BackgroundServiceSample.Services.TimedBackgroundService[0] Hello World! - 9/14/2018 17:48:12
接下来在控制台程序中体验一下。
基于 Generic Host 实现如下的控制台程序,也是执行在 ConfigureServices 中注册一下 TimedBackgroundService 。
class Program { public static async Task Main(string[] args) { var builder = new HostBuilder() .ConfigureLogging(logging => { logging.AddConsole(); }) .ConfigureServices((hostContext, services) => { services.AddHostedService<TimedBackgroundService>(); }); await builder.RunConsoleAsync(); } }
dotnet run 运行程序后 TimedBackgroundService 定时输出了日志:
info: BackgroundServiceSample.Services.TimedBackgroundService[0] Hello World! - 9/14/2018 17:59:37 info: BackgroundServiceSample.Services.TimedBackgroundService[0] Hello World! - 9/14/2018 17:59:42 info: BackgroundServiceSample.Services.TimedBackgroundService[0] Hello World! - 9/14/2018 17:59:47
体验完成。
转:https://www.cnblogs.com/dudu/p/9647619.html
参考:https://docs.microsoft.com/zh-cn/dotnet/architecture/microservices/multi-container-microservice-net-applications/background-tasks-with-ihostedservice