在 .NET 中启动 Windows 后台服务的参数

Question

I am making a Windows Service using .NET's BackgroundService abstract class (similar to the one in this tutorial by Microsoft) but I can't seem to figure out how to get start arguments passed to the service using the Windows Services app. Can someone tell me how to get the arguments I pass in there or what I should be doing?

Answer 1

You have to pass through the args from Main :

public static async Task Main(string[] args)
{
    IHost host = Host.CreateDefaultBuilder(args)
        .ConfigureLogging(options =>
        {
            options.ClearProviders();
            options.AddEventLog();
            options.AddConsole();
        })
        .UseWindowsService(options =>
        {
            options.ServiceName = "WorkerServiceTestArgs";
        })
        .ConfigureServices(services =>
        {
            services.AddSingleton(new MyArgsService(args));
            services.AddHostedService<Worker>();
        })
        .Build();

    await host.RunAsync();
}

Your worker then has a dependency on your service:

public class Worker : BackgroundService
{
    private readonly ILogger<Worker> _logger;
    private readonly MyArgsService _myArgsService;

    public Worker(ILogger<Worker> logger, MyArgsService myArgsService)
    {
        _logger = logger;
        _myArgsService = myArgsService;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            _logger.LogInformation("Worker running at: {time}", DateTimeOffset.Now);
            _logger.LogInformation("Args: {args}", string.Join(";", _myArgsService.GetArgs()));

            await Task.Delay(1000, stoppingToken);
        }
    }
}

eg with this simple Service:

public class MyArgsService
{
    private readonly string[] _args;

    public MyArgsService(string[] args)
    {
        _args = args;
    }

    public string[] GetArgs()
    {
        return _args;
    }
}

Results:

Answer 2

Create a class derived from ServiceBase to receive parameters and implement IHostLifetime .

public class MyServiceLifetime : ServiceBase, IHostLifetime
{
    protected override void OnStart(string[] args)
    {
        base.OnStart(args);
    }

    public public Task WaitForStartAsync(CancellationToken cancellationToken)
        => Task.CompletedTask;
    
    public Task StopAsync(CancellationToken cancellationToken)
        => Task.CompletedTask;
}

Replace this class with UseWindowsService .

using IHost host = Host.CreateDefaultBuilder(args)
    .ConfigureServices(services =>
    {
        services.AddSingleton<IHostLifetime, MyServiceLifetime>();
        services.AddSingleton<JokeService>();
        services.AddHostedService<WindowsBackgroundService>();
    })
    .Build();