使用参数异常的构造函数注入 AppDbContext

Question

我正在尝试在我的类之一中使用 AppDbContext（属于 entity framework 核心）并使用 autofac 对其进行实例化，如下所示：

public class AppDbContext : IdentityDbContext<ApplicationUser>
{
    public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
    {

    }

    protected override void OnModelCreating(ModelBuilder builder)
    {
        builder.Entity<Message>().Property(m => m.Service).HasConversion<int>();
        builder.Entity<ApplicationUser>().HasMany<Message>(m => m.Messages).WithOne(u => u.User).IsRequired();
        base.OnModelCreating(builder);
    }


    public DbSet<Message> Messages { get; set; }
    public DbSet<UsersCredentialsModel> UsersCredentialsModels { get; set; }
    public DbSet<CookieModel> CookieModel { get; set; }


}

我很难完全理解如何实现这个correctly.could有人扔骨头吗？

public static IContainer Startup()
{
    var builder = new ContainerBuilder();
   // builder.RegisterType<AppDbContext>().As<IdentityDbContext<ApplicationUser>>().InstancePerRequest();

    builder.RegisterType<Application>().As<IApplication>();
    builder.RegisterType<RabbitMQImpl>().As<IListenerQueue>().SingleInstance();
    builder.RegisterType<BotFactory>().As<IBotFactory>();
    var instance = QuartzInstance.Instance;
    builder.RegisterType<QueueImpl>().AsImplementedInterfaces();
    builder.RegisterType<ConsumerSchechuler>().AsImplementedInterfaces();
    builder.RegisterType<SchedulerImpl>().AsImplementedInterfaces();
    builder.RegisterModule(new QuartzAutofacJobsModule(typeof(ConsumerSchedulerJob).Assembly)).RegisterAssemblyModules();
    builder.RegisterModule(new QuartzAutofacJobsModule(typeof(DailyCleanUpJob).Assembly)).RegisterAssemblyModules();
    builder.RegisterInstance(QuartzInstance.Instance).AsImplementedInterfaces();
    return builder.Build();

这是我遇到的错误。

DependencyResolutionException: None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'JobsImpl.DailyCleanUpJob' can be invoked with the available services and parameters: Cannot resolve parameter 'Utils.AppDbContext context' of constructor 'Void .ctor(Utils.AppDbContext)'.

Answer 1

一位朋友帮我解决了这个问题：

如果您遇到同样的问题，请使用代码：

var contextOptions = new DbContextOptionsBuilder<AppDbContext>().Options;

//... configure options as necessary

builder.RegisterInstance(contextOptions).As<DbContextOptions<AppDbContext>>();
builder.RegisterType<IdentityDbContext>();
builder.RegisterType<AppDbContext>();

因为 AppDbContext 的构造函数正在接收 DbContextOptions<AppDbContext> 的实例你需要首先实例化它，然后将实例注册为 DbContextOptions<AppDbContext>.

使用参数异常的构造函数注入 AppDbContext

Injecting AppDbContext with constructor with params exception

c#

autofac

.net-core