C# IHostedService的用法 - 在ASP.NET Core中运行后台任务

using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using System.Threading;
using System.Threading.Tasks;

public class TimedHostedService : IHostedService
{
    private readonly ILogger<TimedHostedService> _logger;
    private Timer? _timer;

    public TimedHostedService(ILogger<TimedHostedService> logger)
    {
        _logger = logger;
    }

    public Task StartAsync(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Timed Hosted Service is starting.");

        _timer = new Timer(DoWork, null, TimeSpan.Zero, TimeSpan.FromSeconds(10));

        return Task.CompletedTask;
    }

    private void DoWork(object? state)
    {
        if (!_timer!.Disposed)
        {
            _logger.LogInformation("Timed Hosted Service is working. Time: {Time}", DateTime.Now);
        }
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Timed Hosted Service is stopping.");

        _timer?.Change(Timeout.Infinite, 0);

        return Task.CompletedTask;
    }
}

var builder = WebApplication.CreateBuilder(args);

// 添加 Hosted Service
builder.Services.AddHostedService<TimedHostedService>();

var app = builder.Build();

app.Run();

using Microsoft.Extensions.Hosting;
using System.Threading.Channels;

public class QueuedHostedService : BackgroundService
{
    private readonly ChannelReader<string> _reader;

    public QueuedHostedService(Channel<string> channel)
    {
        _reader = channel.Reader;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        await foreach (var message in _reader.ReadAllAsync(stoppingToken))
        {
            Console.WriteLine($"Processing message: {message}");
            await Task.Delay(1000, stoppingToken); // 模拟处理耗时
        }
    }
}