Quartz.NET是功能齐全的开源作业调度系统，可用于最小的应用程序到大型企业系统。
Quartz.NET具有三个主要概念：
•job：运行的后台任务•trigger：控制后台任务运行的触发器。•scheduler：协调job和trigger
ASP.NET Core通过托管服务对运行“后台任务”具有良好的支持，托管服务在ASP.NET Core应用程序启动时启动，并在应用程序生存期内在后台运行，Quartz.NET版本3.2.0通过Quartz.Extensions.Hosting包引入了对该模式的直接支持，Quartz.Extensions.Hosting可以与ASP.NET Core应用程序一起使用，也可以与基于“通用主机”的工作程序服务一起使用。
虽然.NET Core可以创建“定时”后台服务（例如，每10分钟运行一次任务），但Quartz.NET提供了更为强大的解决方案, 通过使用Cron表达式，您可以确保任务在特定时间（例如，凌晨2:30）运行，或仅在特定的几天运行，或这些时间的任意组合。Quartz.NET还允许您以集群方式运行应用程序的多个实例，以便在任何时候都只能运行一个实例。
安装Quartz.NET
Quartz.NET是一个.NET Standard 2.0 NuGet软件包，所以大部分项目都是支持的，你可以运行安装命令，dotnet add package Quartz.Extensions.Hosting,或者在NNuget可视化安装，如果查看该项目的.csproj，应该是下边这样：
<Project Sdk="Microsoft.NET.Sdk.Worker">
<PropertyGroup>
<TargetFramework>net5.0</TargetFramework>
<UserSecretsId>dotnet-QuartzWorkerService-9D4BFFBE-BE06-4490-AE8B-8AF1466778FD</UserSecretsId>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Microsoft.Extensions.Hosting" Version="5.0.0" />
<PackageReference Include="Quartz.Extensions.Hosting" Version="3.2.3" />
</ItemGroup>
</Project>安装完成以后，这个包会自动安装 Quartz.NET包，接下来，我们需要在我们的应用程序中注册Quartz服务和Quartz 。
添加Quartz.NET hosted service
修改Program.cs，注册服务
代码语言：javascript复制public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureServices((hostContext, services) =>
{
// Add the required Quartz.NET services
services.AddQuartz(q =>
{
// Use a Scoped container to create jobs. I'll touch on this later
q.UseMicrosoftDependencyInjectionScopedJobFactory();
});
// Add the Quartz.NET hosted service
services.AddQuartzHostedService(
q => q.WaitForJobsToComplete = true);
// other config
});
}UseMicrosoftDependencyInjectionScopedJobFactory(),这个地方告诉Quartz.NET注册一个IJobFactory，然后从DI容器中获取Job，这样也可以使用 Scoped 类型的服务。
WaitForJobsToComplete()：当程序关闭时，此设置可确保Quartz.NET在退出之前等待Job正常结束。
如果现在运行您的应用程序，您将看到Quartz服务启动，并将有很多日志输出到控制台：
代码语言：javascript复制info: Quartz.Core.SchedulerSignalerImpl[0]
Initialized Scheduler Signaller of type: Quartz.Core.SchedulerSignalerImpl
info: Quartz.Core.QuartzScheduler[0]
Quartz Scheduler v.3.2.3.0 created.
info: Quartz.Core.QuartzScheduler[0]
JobFactory set to: Quartz.Simpl.MicrosoftDependencyInjectionJobFactory
info: Quartz.Simpl.RAMJobStore[0]
RAMJobStore initialized.
info: Quartz.Core.QuartzScheduler[0]
Scheduler meta-data: Quartz Scheduler (v3.2.3.0) 'QuartzScheduler' with instanceId 'NON_CLUSTERED'
Scheduler class: 'Quartz.Core.QuartzScheduler' - running locally.
NOT STARTED.
Currently in standby mode.
Number of jobs executed: 0
Using thread pool 'Quartz.Simpl.DefaultThreadPool' - with 10 threads.
Using job-store 'Quartz.Simpl.RAMJobStore' - which does not support persistence. and is not clustered.
info: Quartz.Impl.StdSchedulerFactory[0]
Quartz scheduler 'QuartzScheduler' initialized
info: Quartz.Impl.StdSchedulerFactory[0]
Quartz scheduler version: 3.2.3.0
info: Quartz.Core.QuartzScheduler[0]
Scheduler QuartzScheduler_$_NON_CLUSTERED started.
info: Microsoft.Hosting.Lifetime[0]
Application started. Press Ctrl C to shut down.
...现在，您已经将Quartz作为托管服务运行在您的应用程序中，但是现在还没有添加需要运行的Job。
创建一个IJob
这个地方我创建一个简单的服务，并且我可以从构造函数中获取服务。
代码语言：javascript复制using Microsoft.Extensions.Logging;
using Quartz;
using System.Threading.Tasks;
[DisallowConcurrentExecution]
public class HelloWorldJob : IJob
{
private readonly ILogger<HelloWorldJob> _logger;
public HelloWorldJob(ILogger<HelloWorldJob> logger)
{
_logger = logger;
}
public Task Execute(IJobExecutionContext context)
{
_logger.LogInformation("Hello world!");
return Task.CompletedTask;
}
}我还用[DisallowConcurrentExecution]特性，防止Quartz.NET尝试同时运行同一个作业。
设置Job
这个地方通常使用Cron表达式，来设置job的执行时间。
代码语言：javascript复制public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureServices((hostContext, services) =>
{
services.AddQuartz(q =>
{
q.UseMicrosoftDependencyInjectionScopedJobFactory();
// Create a "key" for the job
var jobKey = new JobKey("HelloWorldJob");
// Register the job with the DI container
q.AddJob<HelloWorldJob>(opts => opts.WithIdentity(jobKey));
// Create a trigger for the job
q.AddTrigger(opts => opts
.ForJob(jobKey) // link to the HelloWorldJob
.WithIdentity("HelloWorldJob-trigger") // give the trigger a unique name
.WithCronSchedule("0/5 * * * * ?")); // run every 5 seconds
});
services.AddQuartzHostedService(q => q.WaitForJobsToComplete = true);
// ...
});现在运行应用程序，您将看到和以前相同的启动消息，然后每隔5秒钟就会看到HelloWorldJob写入控制台的信息：
将配置提取到appsettings.json
一般情况，我们都不会把cron表达式写死在代码中，一般是设置在appsettings.json中
代码语言：javascript复制{
"Quartz": {
"HelloWorldJob": "0/5 * * * * ?"
}
}为了更简单的注册服务，这个地方我简单做了一个封装，这样也更灵活。
代码语言：javascript复制public static class ServiceCollectionQuartzConfiguratorExtensions
{
public static void AddJobAndTrigger<T>(
this IServiceCollectionQuartzConfigurator quartz,
IConfiguration config)
where T : IJob
{
// Use the name of the IJob as the appsettings.json key
string jobName = typeof(T).Name;
// Try and load the schedule from configuration
var configKey = $"Quartz:{jobName}";
var cronSchedule = config[configKey];
// Some minor validation
if (string.IsNullOrEmpty(cronSchedule))
{
throw new Exception($"No Quartz.NET Cron schedule found for job in configuration at {configKey}");
}
// register the job as before
var jobKey = new JobKey(jobName);
quartz.AddJob<T>(opts => opts.WithIdentity(jobKey));
quartz.AddTrigger(opts => opts
.ForJob(jobKey)
.WithIdentity(jobName "-trigger")
.WithCronSchedule(cronSchedule)); // use the schedule from configuration
}
}然后修改Program.cs，然后使用扩展方法：
代码语言：javascript复制public class Program
{
public static void Main(string[] args) => CreateHostBuilder(args).Build().Run();
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureServices((hostContext, services) =>
{
services.AddQuartz(q =>
{
q.UseMicrosoftDependencyInjectionScopedJobFactory();
// Register the job, loading the schedule from configuration
q.AddJobAndTrigger<HelloWorldJob>(hostContext.Configuration);
});
services.AddQuartzHostedService(q => q.WaitForJobsToComplete = true);
});
}再次运行该应用程序将提供相同的输出：Job每5秒输入一次信息。
原文作者: andrewlock 原文链接： https://andrewlock.net/using-quartz-net-with-asp-net-core-and-worker-services/[1]
References
[1] https://andrewlock.net/using-quartz-net-with-asp-net-core-and-worker-services/: "https://andrewlock.net/using-quartz-net-with-asp-net-core-and-worker-services/"
