具有多级DI的Quartz.Net作业
具有多级DI的Quartz.Net作业
提问于 2019-06-24 07:52:40
我有一个可以工作的JobFactory : IJobFactory。其中一个依赖项本身依赖于HttpClient，但这似乎不起作用。
例如。
services.AddHttpClient<Dependency>("dependency");
services.AddSingleton(typeof(Dependency));
using (var serviceProvider = services.BuildServiceProvider())
{
var schedulerFactory = new StdSchedulerFactory();
var scheduler = await schedulerFactory.GetScheduler();
scheduler.JobFactory = new JobFactory(serviceProvider);
await scheduler.Start();
var job = JobBuilder.Create<Job1>()
.WithIdentity("job1")
.Build();
var trigger = TriggerBuilder.Create()
.WithIdentity("trigger1")
.StartNow()
.WithSimpleSchedule(x => x
.WithIntervalInSeconds(1)
.RepeatForever())
.Build();
await scheduler.ScheduleJob(job, trigger);
}依赖构造函数为
public Dependency(HttpClient httpClient)
{
// <snipped>
}而作业构造器是
public Job1(Dependency dependency)
{
// <snipped>
}当我尝试运行它时，我被告知该作业抛出了一个未处理的异常。通过我的JobFactory进行调试，我发现httpClient根本没有被注入。不是应该由.AddHttpClient来处理吗？它不能工作是因为DI的多层次吗？有没有可能用另一种方式？
回答 1
Stack Overflow用户
发布于 2019-06-24 08:51:38
这段代码进行重构的时机已经成熟。
将调度器放在IHostedService中，让它来处理调度器的启动。
public interface IHostedService {
//
// Summary:
// Triggered when the application host is ready to start the service.
Task StartAsync(CancellationToken cancellationToken);
//
// Summary:
// Triggered when the application host is performing a graceful shutdown.
Task StopAsync(CancellationToken cancellationToken);
}
public class SchedulerService : IHostedService {
readonly IJobFactory jobFactory;
readonly ISchedulerFactory schedulerFactory
IScheduler scheduler;
public SchedulerService(IJobFactory jobFactory, ISchedulerFactory schedulerFactory) {
this.jobFactory = jobFactory;
this.schedulerFactory = schedulerFactory;
}
public async Task StartAsync(CancellationToken cancellationToken) {
scheduler = await schedulerFactory.GetScheduler();
scheduler.JobFactory = jobFactory;
IJobDetail job = JobBuilder.Create<Job1>()
.WithIdentity("job1")
.Build();
ITrigger trigger = TriggerBuilder.Create()
.WithIdentity("trigger1")
.StartNow()
.WithSimpleSchedule(x => x.WithIntervalInSeconds(1)
.RepeatForever())
.Build();
await scheduler.ScheduleJob(job, trigger);
await scheduler.Start(cancellationToken);
}
public Task StopAsync(CancellationToken cancellationToken) {
return scheduler.Shutdown(cancellationToken);
}
}现在，通过将所有类型添加到服务集合中，可以在启动时干净地完成配置
class Program {
static async Task Main(string[] args) {
var services = new ServiceCollection();
//...
services.AddHttpClient<IDependency, Dependency>();
services.AddScoped<Job1>();
services.AddTransient<ISchedulerFactory, StdSchedulerFactory>();
services.AddTransient<IJobFactory>(serviceProvider => new JobFactory(serviceProvider));
services.AddTransient<IHostedService, SchedulerService>();
//...
IServiceProvider serviceProvider = services.BuildServiceProvider();
var service = serviceProvider.GetRequiredService<IHostedService>();
await service.StartAsync();
Console.ReadKey();
}
}因此，现在服务将管理启动，并根据需要注入所有必要的依赖项。
包括类型化的客户端Dependency类，假设如下
public class Dependency : IDependency {
public Dependency(HttpClient httpClient) {
// <snipped>
}
}
public class Job1: IJob {
public Job1(IDependency dependency) {
// <snipped>
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/56728515
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