背景
之前一直有朋友问，.Net Core + Linux环境有没有类似Windows服务的东西。其实是有的，我了解的方法有两种：
#1 创建一个ASP.Net Core的Web项目（如Web API），然后通过添加中间件（Middleware）的方式来启动任务；
#2 创建一个.Net Core的项目，添加Host，Dependency Injection，Configuration等组件，然后通过Main方法或中间件的方式启动服务。
但是，上述两种方法都有点不足，如：
#1 会把Web的生命周期引进来，但实际上，我们并不需要Web的功能，如Controller；
#2 本身是没有问题的，但是对开发者的要求相对高一点点，需要对.Net Core的各个组成部分都有一定的认识，简而言之，门槛有一丢丢高。
.Net Core 2.1推出了一个Generic Host的概念，可以很好的解决上面两种方法的不足：
至于为什么选择Quartz来做调度，我想可能是因为情怀吧，因为之前是用的TopShelf+Quartz，其实Hangfire也不错。
使用Hosted Service
1. 创建一个控制台程序。
2. 添加Host Nuget包。
Install-Package Microsoft.Extensions.Hosting -Version 2.1.0
Install-Package Microsoft.Extensions.Configuration.FileExtensions -Version 2.1.0
Install-Package Microsoft.Extensions.Configuration.Json -Version 2.1.0
Install-Package Microsoft.Extensions.Configuration.EnvironmentVariables -Version 2.1.0
Install-Package Microsoft.Extensions.Configuration.CommandLine -Version 2.1.0
Install-Package Microsoft.Extensions.Logging.Console -Version 2.1.0
Install-Package Microsoft.Extensions.Logging.Debug -Version 2.1.0
3. 添加一个基于Timer的简单Hosted Service（用于简单演示），继承IHostedService。
internal class TimedHostedService : IHostedService, IDisposable{ ???private readonly ILogger _logger; ???private Timer _timer; ???public TimedHostedService(ILogger<TimedHostedService> logger) ???{ ???????_logger = logger; ???} ???public Task StartAsync(CancellationToken cancellationToken) ???{ ???????_logger.LogInformation("Timed Background Service is starting."); ???????_timer = new Timer(DoWork, null, TimeSpan.Zero, TimeSpan.FromSeconds(5)); ???????return Task.CompletedTask; ???} ???private void DoWork(object state) ???{ ???????_logger.LogInformation(string.Format("[{0:yyyy-MM-dd hh:mm:ss}]Timed Background Service is working.", DateTime.Now)); ???} ???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(); ???}}4. Main函数中添加Host的相关代码。
var host = new HostBuilder() ???.ConfigureHostConfiguration(configHost => ???{ ???????configHost.SetBasePath(Directory.GetCurrentDirectory());
???????//configHost.AddJsonFile("hostsettings.json", true, true); ???????configHost.AddEnvironmentVariables("ASPNETCORE_"); ???????//configHost.AddCommandLine(args); ???}) ???.ConfigureAppConfiguration((hostContext, configApp) => ???{ ???????configApp.AddJsonFile("appsettings.json", true); ???????configApp.AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", true); ???????configApp.AddEnvironmentVariables(); ???????//configApp.AddCommandLine(args); ???}) ???.ConfigureServices((hostContext, services) => ???{ ???????services.AddLogging(); ???????services.AddHostedService<TimedHostedService>(); ???}) ???.ConfigureLogging((hostContext, configLogging) => ???{ ???????configLogging.AddConsole(); ???????if (hostContext.HostingEnvironment.EnvironmentName == EnvironmentName.Development) ???????{ ???????????configLogging.AddDebug(); ???????} ???}) ???.UseConsoleLifetime() ???.Build();host.Run();5. 查看结果
6. 代码解析
a. Host配置
.ConfigureHostConfiguration(configHost =>
{
//配置根目录
configHost.SetBasePath(Directory.GetCurrentDirectory());
//读取host的配置json，和appsetting类似，暂不需要先注释掉，可根据需要开启
//configHost.AddJsonFile("hostsettings.json", true, true);
//读取环境变量，Asp.Net core默认的环境变量是以ASPNETCORE_作为前缀的，这里也采用此前缀以保持一致
configHost.AddEnvironmentVariables("ASPNETCORE_");
//可以在启动host的时候之前可传入参数，暂不需要先注释掉，可根据需要开启
//configHost.AddCommandLine(args);
})
b. App配置
.ConfigureAppConfiguration((hostContext, configApp) =>
{
//读取应用的配置json
configApp.AddJsonFile("appsettings.json", true);
//读取应用特定环境下的配置json
configApp.AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", true);
//读取环境变量
configApp.AddEnvironmentVariables();
//可以在启动host的时候之前可传入参数，暂不需要先注释掉，可根据需要开启
//configApp.AddCommandLine(args);
})
c. 配置服务及依赖注入注册，注：没有Middleware的配置了。
.ConfigureServices((hostContext, services) =>
???{
//添加日志Service
services.AddLogging();
//添加Timer Hosted Service
services.AddHostedService<TimedHostedService>();
???})
d. 日志配置
.ConfigureLogging((hostContext, configLogging) =>
???{
//输出控制台日志
??????? configLogging.AddConsole();
//开发环境输出Debug日志
??????? if (hostContext.HostingEnvironment.EnvironmentName == EnvironmentName.Development)
??????? {
??????????? configLogging.AddDebug();
??????? }
???})
e. 使用控制台生命周期
.UseConsoleLifetime() //使用Ctrl + C退出
其它详细的可参考：https://docs.microsoft.com/en-us/aspnet/core/fundamentals/host/generic-host?view=aspnetcore-2.1
使用Quartz
1. 添加Host Nuget包。
Install-Package Quartz -Version 3.0.5Install-Package Quartz.Plugins -Version 3.0.5
2. Quartz配置。
之前Quartz的配置是放在quartz.config里面的，但我更喜欢使用appsettings.json，因此，把配置改成了从appsettings.json。
先建一个QuartzOption的类：
/// <summary>/// 更多设置请参考：https://github.com/quartznet/quartznet/blob/master/src/Quartz/Impl/StdSchedulerFactory.cs/// </summary>public class QuartzOption{ ???public QuartzOption(IConfiguration config) ???{ ???????if (config == null) ???????{ ???????????throw new ArgumentNullException(nameof(config)); ???????} ???????var section = config.GetSection("quartz"); ???????section.Bind(this); ???} ???public Scheduler Scheduler { get; set; } ???public ThreadPool ThreadPool { get; set; } ???public Plugin Plugin { get; set; } ???public NameValueCollection ToProperties() ???{ ???????var properties = new NameValueCollection ???????{ ???????????["quartz.scheduler.instanceName"] = Scheduler?.InstanceName, ???????????["quartz.threadPool.type"] = ThreadPool?.Type, ???????????["quartz.threadPool.threadPriority"] = ThreadPool?.ThreadPriority, ???????????["quartz.threadPool.threadCount"] = ThreadPool?.ThreadCount.ToString(), ???????????["quartz.plugin.jobInitializer.type"] = Plugin?.JobInitializer?.Type, ???????????["quartz.plugin.jobInitializer.fileNames"] = Plugin?.JobInitializer?.FileNames ???????}; ???????return properties; ???}}public class Scheduler{ ???public string InstanceName { get; set; }}public class ThreadPool{ ???public string Type { get; set; } ???public string ThreadPriority { get; set; } ???public int ThreadCount { get; set; }}public class Plugin{ ???public JobInitializer JobInitializer { get; set; }}public class JobInitializer{ ???public string Type { get; set; } ???public string FileNames { get; set; }}3. 重写JobFactory。
public class JobFactory : IJobFactory{ ???private readonly IServiceProvider _serviceProvider; ???public JobFactory(IServiceProvider serviceProvider) ???{ ???????_serviceProvider = serviceProvider; ???} ???public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler) ???{ ???????var job = _serviceProvider.GetService(bundle.JobDetail.JobType) as IJob; ???????return job; ???} ???public void ReturnJob(IJob job) ???{ ???}}4. 编写Quartz Hosted Service
public class QuartzService : IHostedService{ ???private readonly ILogger _logger; ???private readonly IScheduler _scheduler; ???public QuartzService(ILogger<QuartzService> logger, IScheduler scheduler) ???{ ???????_logger = logger; ???????_scheduler = scheduler; ???} ???public async Task StartAsync(CancellationToken cancellationToken) ???{ ???????_logger.LogInformation("开始Quartz调度..."); ???????await _scheduler.Start(cancellationToken); ???} ???public async Task StopAsync(CancellationToken cancellationToken) ???{ ???????_logger.LogInformation("停止Quartz调度..."); ???????await _scheduler.Shutdown(cancellationToken); ???}}5. 准备appsettings.json
{ ?"quartz": { ???"scheduler": { ?????"instanceName": "HostedService.Quartz" ???}, ???"threadPool": { ?????"type": "Quartz.Simpl.SimpleThreadPool, Quartz", ?????"threadPriority": "Normal", ?????"threadCount": 10 ???}, ???"plugin": { ?????"jobInitializer": { ???????"type": "Quartz.Plugin.Xml.XMLSchedulingDataProcessorPlugin, Quartz.Plugins", ???????"fileNames": "quartz_jobs.xml" ?????} ???} ?}}6. 编写一个TestJob
public class TestJob : IJob{ ???private readonly ILogger _logger; ???public TestJob(ILogger<TestJob> logger) ???{ ???????_logger = logger; ???} ???public Task Execute(IJobExecutionContext context) ???{ ???????_logger.LogInformation(string.Format("[{0:yyyy-MM-dd hh:mm:ss:ffffff}]任务执行！", DateTime.Now)); ???????return Task.CompletedTask; ???}}7. 准备Quartz的调度文件quartz_jobs.xml
<?xml version="1.0" encoding="UTF-8"?><job-scheduling-data xmlns="http://quartznet.sourceforge.net/JobSchedulingData" ???????xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ????????????????version="2.0"> ?<processing-directives> ???<overwrite-existing-data>true</overwrite-existing-data> ?</processing-directives> ?<schedule> ???<job> ?????<name>TestJob</name> ?????<group>TestGroup</group> ?????<description>测试任务</description> ?????<job-type>HostedService.Quartz.Jobs.TestJob, HostedService.Quartz</job-type> ?????<durable>true</durable> ?????<recover>false</recover> ???</job> ???<trigger> ?????<simple> ???????<name>TestTrigger</name> ???????<group>TestGroup</group> ???????<description>测试触发器</description> ???????<job-name>TestJob</job-name> ???????<job-group>TestGroup</job-group> ???????<repeat-count>-1</repeat-count> ???????<repeat-interval>2000</repeat-interval> ?????</simple> ???</trigger> ???<!--<trigger> ?????<cron> ???????<name>TestTrigger</name> ???????<group>TestGroup</group> ???????<description>测试触发器</description> ???????<job-name>TestJob</job-name> ???????<job-group>TestGroup</job-group> ???????<cron-expression>0/2 * * * * ?</cron-expression> ?????</cron> ???</trigger>--> ?</schedule></job-scheduling-data>
8. 注册Quartz Hosted Service和TestJob
.ConfigureServices((hostContext, services) =>{ ???services.AddLogging(); ???//services.AddHostedService<TimedHostedService>(); ???services.AddSingleton<IJobFactory, JobFactory>(); ???services.AddSingleton(provider => ???{ ???????var option = new QuartzOption(hostContext.Configuration); ???????var sf = new StdSchedulerFactory(option.ToProperties()); ???????var scheduler = sf.GetScheduler().Result; ???????scheduler.JobFactory = provider.GetService<IJobFactory>(); ???????return scheduler; ???}); ???services.AddHostedService<QuartzService>(); ???services.AddSingleton<TestJob, TestJob>();})9. 查看结果
10. 补充说明。
Generic Service默认的环境是Production，如果想使用Development环境，可以在项目属性的Debug页签中添加环境变量来实现。
源码地址
https://github.com/ErikXu/.NetCoreTips/tree/master/HostedService.Quartz
便捷使用
https://www.nuget.org/packages/Quartz.HostedService/
https://github.com/ErikXu/Quartz.HostedService
.Net Core小技巧 - Hosted Services + Quartz实现定时任务调度
原文地址：https://www.cnblogs.com/Erik_Xu/p/9219307.html