我正在使用.NET 5,想要运行一个后台任务,使用IHostedService
类,如下所示:
public class PasargadJobs : IHostedService, IDisposable
{
private Timer _timer = null!;
readonly ITerminalService _terminalService;
readonly IMessageService _messageService;
readonly IMerchantService _merchantService;
public PasargadJobs(
IMerchantService merchantService,
ITerminalService terminalService,
IMessageService messageService)
{
_messageService = messageService;
_terminalService = terminalService;
_merchantService = merchantService;
}
//other parts of code are removed for short code
}
所以我必须将它注入到服务集合中,正如您所看到的:
services.AddHostedService<PasargadJobs>();
但是在添加这个后,我遇到了以下错误:
System.AggregateException:“无法构造某些服务(验证服务描述符时出错'ServiceType: Microsoft.Extensions.Hosting.IHostedService Lifetime: Singleton ImplementationType: MIMS.Portal.ScheduleJobs.PasargadJobs':无法从单例'Microsoft.Extensions.Hosting.IHostedService'中使用范围服务 'Microsoft.EntityFrameworkCore.DbContextOptions`1[MIMS.Portal.Infrustructure.Repositories.AppDbContext]'。”)
这是我的startup.cs文件:
services.AddExpressiveAnnotations();
//--- DB Context ---//
services.AddTransient<AppDbContext, AppDbContext>();
//--- Repositories ---//
services.AddTransient(typeof(IGenericRepository<>), typeof(GenericRepository<>));
services.AddTransient<IMerchantRepository, MerchantRepository>();
services.AddTransient<IBankAccountRepository, BankAccountRepository>();
services.AddTransient<IBankRepository, BankRepository>();
services.AddTransient<IGeoRepository, GeoRepository>();
services.AddTransient<IDepartmentRepository, DepartmentRepository>();
services.AddTransient<IDeviceRepository, DeviceRepository>();
services.AddTransient<IInvoiceRepository, InvoiceRepository>();
services.AddTransient<IStoreRepository, StoreRepository>();
services.AddTransient<ITerminalRepository, TerminalRepository>();
services.AddTransient<ITicketRepository, TicketRepository>();
services.AddTransient<IUserRepository, UserRepository>();
services.AddTransient<IFileRepository, FileRepository>();
services.AddTransient<IPartnerRepository, PartnerRepository>();
services.AddTransient<IStoreScopeRepository, StoreScopeRepository>();
services.AddTransient<ICommentRepository, CommentRepository>();
services.AddTransient<INewsRepository, NewsRepository>();
services.AddTransient<IPosBrandRepository, PosBrandRepository>();
//-- Services --//
services.AddTransient<IMerchantService, MerchantService>();
services.AddTransient<IBankAccountService, BankAccountService>();
services.AddTransient<IBankService, BankService>();
services.AddTransient<IGeoService, GeoService>();
services.AddTransient<IDepartmentService, DepartmentService>();
services.AddTransient<IDeviceService, DeviceService>();
services.AddTransient<IInvoiceService, InvoiceService>();
services.AddTransient<IStoreService, StoreService>();
services.AddTransient<ITerminalService, TerminalService>();
services.AddTransient<ITicketService, TicketService>();
services.AddTransient<IUsersService, UsersService>();
services.AddTransient<IFilesManagerService, FilesManagerService>();
services.AddTransient<IMessageService, MessageService>();
services.AddTransient<IPartnerService, PartnerService>();
services.AddTransient<IStoreScopeService, StoreScopeService>();
services.AddTransient<INewsService, NewsService>();
services.AddTransient<ICommentService, CommentService>();
services.AddTransient<IPosBrandService, PosBrandService>();
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services
.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(option =>
{
option.TokenValidationParameters = new TokenValidationParameters
{
ValidateIssuer = true,
ValidateAudience = true,
ValidateLifetime = true,
ValidateIssuerSigningKey = true,
ValidIssuer = "localhost",
ValidAudience = "localhost",
IssuerSigningKey = new SymmetricSecurityKey(
Encoding.UTF8.GetBytes("wevhgfrtyhasdfghjklzxcvbnm"))
};
});
services.AddHostedService<PasargadJobs>();
_serviceScopeFactory = serviceScopeFactory; var scope = _serviceScopeFactory.CreateScope(); var _terminalService = scope.ServiceProvider.GetRequiredService();
var _merchantService = scope.ServiceProvider.GetRequiredService();
var _messageService = scope.ServiceProvider.GetRequiredService();
} - Ehsan Akbarvar _terminalService = ...
而不是_terminalService = ...
这样你会将服务分配给本地变量,而字段_terminalService
仍然为null
。另外不要在构造函数中创建服务,这基本上会使所有服务成为单例。 - Christian Heldscope
吗?你正在使用using
,它会在作用域结束时自动为我处理。我有什么遗漏吗? - Konrad Viltersten