Getting singleton services in IActionFilter-CodePudding

This is probably a basic question, but I can't find a good reference.

I have a simple filter and it executes fine.

     public class MyFilter: IActionFilter
        {
            public void OnActionExecuting(ActionExecutingContext context)
            {
            }
    
            public void OnActionExecuted(ActionExecutedContext context)
            {
                
                // this fails since my singleton service is not in the collection
                context.HttpContext.RequestServices
                     .GetRequiredService<IConnectionMultiplexer>();
            }
        }

When the filter executes and I consult context.HttpContext.RequestServices, I only find services that were registered as scoped. Is it possible for me to get a service registered as a singleton (which is what my IConnectionMultiplexer is)?

What I'm trying to do is execute a DB lookup as part of the pipeline, to augment the response's headers with my customer headers. Alternatives welcome as well.

CodePudding user response：

You can create a constructor for the filter and can access the singleton service directly right?

builder.Services.AddSingleton<DemoService>();
builder.Services.AddScoped<CustomFilter>();

And in the filter.

public class CustomFilter : IActionFilter
{
    private readonly DemoService _demoService;

    public CustomFilter(DemoService demoService)
    {
        _demoService = demoService;
    }
    public void OnActionExecuted(ActionExecutedContext context)
    {   
    }

    public void OnActionExecuting(ActionExecutingContext context)
    {
    }
}