Question 87736 in ASP.NET Question posted in
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DbContext error when using it for ActionFilter in ASP.NET Core MVC

I need to log certain user actions, such as Login, logout, CRUD, etc. and save to a table called AuditRecords. I have a DbContext called AuditContext:

I have learned that applying an ActionFilter and decorate a controllermethod with it is the way to go. The AuditContext is causing a red squiggly asking for the ‘options’, which baffles me. I have tried DI, but got the same results. Any thoughts? I am on DotNet 5.01, but I tried it withg DotNet 6 as well with the same results.

EDIT
I changed the AuditAttribute and Context to make it as straightforward as possible and by using Dependency Injection, as advised. But the problem is still not solved.

 public class Audit
{
    //Audit Properties
    public Guid AuditID { get; set; }
    public string UserName { get; set; }
    public string IPAddress { get; set; }
    public string AreaAccessed { get; set; }
    public DateTime Timestamp { get; set; }

    //Default Constructor
    public Audit() { }
}

public class AuditContext : DbContext
{
    public DbSet<Audit> AuditRecords { get; set; }
}
public class HomeController : Controller
{
   //red squiggly under [Audit] decoration with error of no formal
   //parameter 'context' in AuditAttribute.AuditAttribute(AuditContext)
    [Audit]  
    public IActionResult Privacy()
    {
        return View();
    }

//AuditAttribute class
using Microsoft.AspNetCore.Mvc.Filters;
using System;

namespace LoggingDemoMVC.Filters
{
public class AuditAttribute : ActionFilterAttribute
{
    private readonly AuditContext _context;

    public AuditAttribute(AuditContext context)
    { 
        _context = context;
    } 

    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        //Stores the Request in an Accessible object
        var request = filterContext.HttpContext.Request;
        //Generate an audit
        Audit audit = new Audit()
        {
            //Your Audit Identifier     
            AuditID = Guid.NewGuid(),
            //Our Username (if available)
            UserName = (filterContext.HttpContext.User.Identity.IsAuthenticated) ? filterContext.HttpContext.User.Identity.Name : "Anonymous",
            //The IP Address of the Request
            IPAddress = request.Path,
            //The URL that was accessed
            AreaAccessed = request.HttpContext.Request.Path,
            //Creates our Timestamp
            Timestamp = DateTime.UtcNow
        };

        //Stores the Audit in the Database
        
        _context.AuditRecords.Add(audit);
        _context.SaveChanges();

        //Finishes executing the Action as normal 

        base.OnActionExecuting(filterContext);
    }
}

}

Tags:

2

Answers


  1. 0

    WebAppContext expects a DbContext<WebAppContext> to be passed into its constructor . However , you are calling the constructor without providing anything :

    WebAppContext _context = new WebAppContext()

    To fix the issue , you can just plug into the Dependency Injection system that you’ve set up

    public class CustomFilter : IActionFilter
    {
        private readonly WebAppContext _context;
        public CustomFilter(WebAppContext context)
        {
            _context = context;
        }
      
        public void OnActionExecuting(ActionExecutingContext context)
        {
            //.......
                
            _context.AuditRecords.Add(...);
            _context.SaveChanges();
        }
    }

    Simple Demo :

    model

    public class Audit
    {
        public int ID { get; set; }
        public string Name { get; set; }
    }

    DataContext

     public class WebAppContext : DbContext
    {
        public WebAppContext(DbContextOptions<WebAppContext> options) : base(options)
        {

        }
        public DbSet<Audit> AuditRecords { get; set; }
    }

    Custom Filter

    public class CustomFilter :Attribute,IActionFilter
    {
        private readonly WebAppContext _context;
        public CustomFilter(WebAppContext context)

        {
            _context = context;
        }

        public void OnActionExecuted(ActionExecutedContext context)
        {
            Console.WriteLine("end");
        }

        public void OnActionExecuting(ActionExecutingContext context)
        {
            Audit audit = new Audit();
           
            audit.Name = "mike";
                
            _context.AuditRecords.Add(audit);
            _context.SaveChanges();
        }
    }

    Startup

    public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllersWithViews();
            //config database
            services.AddDbContext<WebAppContext>(option=>option.UseSqlServer(Configuration.GetConnectionString("default")));
            //add filter
            services.AddScoped<CustomFilter>();
        }

    controller

    [TypeFilter(typeof(CustomFilter))]
public IActionResult Privacy()
{
    return View();
}

    when I access Privacy method , The database will add a row of data

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  2. 0

    First, add the Nuget package Microsoft.EntityFrameworkCore.SqlServer to your project.
    Then, add the following code to the ConfigureServices method of your Startup class:

    services.AddDbContext<WebAppContext>(options =>
 options.UseSqlServer("[your connectionstring here]"));

    That’s the bare minimum and this will enable you to inject the DbContext into the ActionFilter.

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