I need to use entity framework in my custom authorization handler. But it's not working. It fails on runtime. I am getting this error in response body:

```
<h2 class="stackerror">InvalidOperationException: Cannot consume scoped service &#x27;SomeDbContext&#x27; from singleton &#x27;Microsoft.AspNetCore.Authorization.IAuthorizationHandler&#x27;.</h2>

```

I can't inject DB Context like this. How can I use db context in my custom authorization handler? 

In my custom authorization handler class:

```
public class CustomAuthorizationHandler : AuthorizationHandler<CustomAuthRequirement>
{
    private readonly SomeDbContext _dbContext;

    public CustomAuthorizationHandler(SomeDbContext context)
    {
        _dbContext = context;
    }

    protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, CustomAuthRequirement requirement)
    {
        ...

        //Some datatable read operations with _dbContext

        ...
    }
}

```

In my Startup.cs:

```
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddDbContext<SomeDbContext>(options =>
              options.UseNpgsql(Configuration.GetConnectionString("DefaultConnection")));

        services.AddSingleton<IAuthorizationPolicyProvider, CustomAuthPolicyProvider>();

        services.AddSingleton<IAuthorizationHandler, CustomAuthorizationHandler>();

        ...
    }

```