3

我有以下计时器可以在 .Net 核心 Ihosted 服务中运行，

TimeSpan ScheduledTimespan;
string[] formats = { @"hh\:mm\:ss", "hh\\:mm" };
string strTime = Startup.Configuration["AppSettings:JobStartTime"].ToString();
var success = TimeSpan.TryParseExact(strTime, formats, CultureInfo.InvariantCulture, out ScheduledTimespan);
Timer _timer = new Timer(JobToRun, null, TimeSpan.Zero, ScheduledTimespan);

我正在使用这个特定的重载，

public Timer(TimerCallback callback, object state, TimeSpan dueTime, TimeSpan period);

但是JobToRun一旦控制到达它就会执行。如何让它每天在一天中的特定时间运行？提前致谢。

4

2 回答 2

9

以下函数返回解析的作业运行时间

private static TimeSpan getScheduledParsedTime()
{
     string[] formats = { @"hh\:mm\:ss", "hh\\:mm" };
     string jobStartTime = "07:10";
     TimeSpan.TryParseExact(jobStartTime, formats, CultureInfo.InvariantCulture, out TimeSpan ScheduledTimespan);
     return ScheduledTimespan;
}

以下函数返回当前时间的延迟时间。如果一天中的当前时间超过了作业运行时间，则会向作业运行添加适当的延迟，如下所示，

private static TimeSpan getJobRunDelay()
{
    TimeSpan scheduledParsedTime = getScheduledParsedTime();
    TimeSpan curentTimeOftheDay = TimeSpan.Parse(DateTime.Now.TimeOfDay.ToString("hh\\:mm"));
    TimeSpan delayTime = scheduledParsedTime >= curentTimeOftheDay
        ? scheduledParsedTime - curentTimeOftheDay
        : new TimeSpan(24, 0, 0) - curentTimeOftheDay + scheduledParsedTime;
    return delayTime;
}

下面的计时器将methodToExecute根据JobRunDelay每天调用

_timer = new Timer(methodToExecute, null, getJobRunDelay(), new TimeSpan(24, 0, 0));
于 2020-01-14T08:46:48.460 回答
8

使用 Cron 作业

  1. 创建 ASP.NET Core Web 项目

  2. 添加 NuGet 包 Microsoft.Extensions.Hosting

  3. 添加 NuGet 包 Cronos

  4. Crete 抽象类 CronJobService - 在这个 CronJobService 中，我们使用计时器来跟踪时间，并在时间达到计划时触发后台任务

    public abstract class CronJobService : IHostedService, IDisposable
{
  private System.Timers.Timer _timer;
  private readonly CronExpression _expression;
  private readonly TimeZoneInfo _timeZoneInfo;

  protected CronJobService(string cronExpression, TimeZoneInfo timeZoneInfo)
  {
    _expression = CronExpression.Parse(cronExpression);
    _timeZoneInfo = timeZoneInfo;
  }

  public virtual async Task StartAsync(CancellationToken cancellationToken)
  {
   await ScheduleJob(cancellationToken);
  }

  protected virtual async Task ScheduleJob(CancellationToken cancellationToken)
  {
     var next = _expression.GetNextOccurrence(DateTimeOffset.Now, _timeZoneInfo);
     if (next.HasValue)
     {
       var delay = next.Value - DateTimeOffset.Now;
       if (delay.TotalMilliseconds <= 0)   // prevent non-positive values from being passed into Timer
       {
          await ScheduleJob(cancellationToken);
       }
       _timer = new System.Timers.Timer(delay.TotalMilliseconds);
       _timer.Elapsed += async (sender, args) =>
       {
          _timer.Dispose();  // reset and dispose timer
          _timer = null;

          if (!cancellationToken.IsCancellationRequested)
          {
              await DoWork(cancellationToken);
          }

          if (!cancellationToken.IsCancellationRequested)
          {
              await ScheduleJob(cancellationToken);    // reschedule next
          }
       };
       _timer.Start();
     }
     await Task.CompletedTask;
  }

  public virtual async Task DoWork(CancellationToken cancellationToken)
  {
     await Task.Delay(5000, cancellationToken);  // do the work
  }

  public virtual async Task StopAsync(CancellationToken cancellationToken)
  {
    _timer?.Stop();
    await Task.CompletedTask;
  }

  public virtual void Dispose()
  {
    _timer?.Dispose();
  }
}

  5. 从 CronJobService 继承

      public class XXXCronJob:CronJobService
  {
    private readonly ILogger<CronJob> _logger;

    public XXXCronJob(IScheduleConfig<CronJob > config, ILogger<CronJob> logger)
    : base(config.CronExpression, config.TimeZoneInfo)
    {
     _logger = logger;
    }

    public override Task StartAsync(CancellationToken cancellationToken)
    {
     _logger.LogInformation("CronJob  starts.");
     return base.StartAsync(cancellationToken);
    }

    public override Task DoWork(CancellationToken cancellationToken)
    {
     _logger.LogInformation($"{DateTime.Now:hh:mm:ss} CronJob  is working.");
     return Task.CompletedTask;
    }

    public override Task StopAsync(CancellationToken cancellationToken)
    {
     _logger.LogInformation("CronJob  is stopping.");
     return base.StopAsync(cancellationToken);
    }
 }

  6. 添加新接口 IScheduleConfig

     public interface IScheduleConfig<T>
 {
   string CronExpression { get; set; }
   TimeZoneInfo TimeZoneInfo { get; set; }
 }

  7. 实施 IScheduleConfig

     public class ScheduleConfig<T> : IScheduleConfig<T>
 {
   public string CronExpression { get; set; }
   public TimeZoneInfo TimeZoneInfo { get; set; }
 }

  8. 添加扩展类 ScheduledServiceExtensions

     public static class ScheduledServiceExtensions
 {
    public static IServiceCollection AddCronJob<T>(this IServiceCollection services, Action<IScheduleConfig<T>> options) where T : CronJobService
    {
       if (options == null)
       {
          throw new ArgumentNullException(nameof(options), @"Please provide Schedule Configurations.");
       }
       var config = new ScheduleConfig<T>();
       options.Invoke(config);
       if (string.IsNullOrWhiteSpace(config.CronExpression))
       {
          throw new ArgumentNullException(nameof(ScheduleConfig<T>.CronExpression), @"Empty Cron Expression is not allowed.");
       }

       services.AddSingleton<IScheduleConfig<T>>(config);
       services.AddHostedService<T>();
      return services;
    }
 }

  9. 使用泛型安排多个 Cron 作业

     public void ConfigureServices(IServiceCollection services)
 {
   services.AddCronJob<XXXCronJob>(c =>
   {
     c.TimeZoneInfo = TimeZoneInfo.Local;
     c.CronExpression = @"00 05 * * *";
   });
   services.AddCronJob<YYYCronJob>(c =>
   {
     c.TimeZoneInfo = TimeZoneInfo.Local;
     c.CronExpression = @"00 08 * * *";
   });
   services.AddCronJob<ZZZCronJob>(c =>
   {
     c.TimeZoneInfo = TimeZoneInfo.Local;
     c.CronExpression = @"30 14 * * *";
   });
 }

    第一个是 05:00 AM。

    第二个是 08:00 AM

    最后一个是下午 14:30。

于 2020-11-14T20:17:27.963 回答