netcore的依赖注入，在BackgroundService中使用Scope注入的服务

1.BackgroundService注入的服务默认为Singleton范围：

 services.AddHostedService<SyncDataJob>();
 或者
 services.AddSingleton<IHostedService,SyncDataJob>()；

2.运行时，会报错：
Cannot consume scoped service from singleton

3.解决办法：
a:使用IServiceScopeFactory 工厂

       public SyncDataJob(IServiceScopeFactory serviceScopeFactory)
        {
            _serviceScopeFactory = serviceScopeFactory;
        }
        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            using (var scope = _serviceScopeFactory.CreateScope())
            {
                ISyncConfigService syncConfigService=scope.ServiceProvider.GetRequiredService<ISyncConfigService>();
                var syncConfigEntity = syncConfigService.GetEntityByType(CONFIG_TYPE);
                while (!stoppingToken.IsCancellationRequested)
                {
                    //Doing Somethings
                    var isSuc = this.AddFetchJob();
                    await Task.Delay(syncConfigEntity.Data.delay * 1000, stoppingToken);
                }
            }
        }

https://www.5axxw.com/questions/content/rvyfhj
b:使用IServiceProvider

public ConsumeScopedServiceHostedService(IServiceProvider services, 
        ILogger<ConsumeScopedServiceHostedService> logger)
    {
        Services = services;
        _logger = logger;
    }

    public IServiceProvider Services { get; }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        _logger.LogInformation(
            "Consume Scoped Service Hosted Service running.");
 		using (var scope = Services.CreateScope())
        {
            var scopedProcessingService = 
                scope.ServiceProvider
                    .GetRequiredService<IScopedProcessingService>();

            await scopedProcessingService.DoWork(stoppingToken);
        }
    }

https://docs.microsoft.com/zh-cn/aspnet/core/fundamentals/host/hosted-services?view=aspnetcore-6.0&tabs=visual-studio