如何在后台的计时器上写入数据库。例如,检查邮件并将新信件添加到数据库中。在示例中,我在写入数据库之前简化了代码。
Microsoft 示例中的类名。录音类本身:
namespace EmailNews.Services
{
internal interface IScopedProcessingService
{
void DoWork();
}
internal class ScopedProcessingService : IScopedProcessingService
{
private readonly ApplicationDbContext _context;
public ScopedProcessingService(ApplicationDbContext context)
{
_context = context;
}
public void DoWork()
{
Mail mail = new Mail();
mail.Date = DateTime.Now;
mail.Note = "lala";
mail.Tema = "lala";
mail.Email = "lala";
_context.Add(mail);
_context.SaveChangesAsync();
}
}
}
定时器类:
namespace EmailNews.Services
{
#region snippet1
internal class TimedHostedService : IHostedService, IDisposable
{
private readonly ILogger _logger;
private Timer _timer;
public TimedHostedService(IServiceProvider services, ILogger<TimedHostedService> logger)
{
Services = services;
_logger = logger;
}
public IServiceProvider Services { get; }
public Task StartAsync(CancellationToken cancellationToken)
{
_logger.LogInformation("Timed Background Service is starting.");
_timer = new Timer(DoWork, null, TimeSpan.Zero,
TimeSpan.FromMinutes(1));
return Task.CompletedTask;
}
private void DoWork(object state)
{
using (var scope = Services.CreateScope())
{
var scopedProcessingService =
scope.ServiceProvider
.GetRequiredService<IScopedProcessingService>();
scopedProcessingService.DoWork();
}
}
public Task StopAsync(CancellationToken cancellationToken)
{
_logger.LogInformation("Timed Background Service is stopping.");
_timer?.Change(Timeout.Infinite, 0);
return Task.CompletedTask;
}
public void Dispose()
{
_timer?.Dispose();
}
}
#endregion
}
启动:
services.AddHostedService<TimedHostedService>();
services.AddScoped<IScopedProcessingService, ScopedProcessingService>();
似乎一切都像示例中那样完成,但没有任何内容添加到数据库中,不是吗?