I am trying to implement a simple custom error handling page, after went through different approaches online, I have the following code:

Statup.cs

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{       
    app.UseExceptionHandler("/Error");

    app.UseStaticFiles();

    app.UseAuthentication();

    app.UseStatusCodePagesWithRedirects("/Error/StatusCode/{0}");

    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
        endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}/{id?}");
    });
}

ErrorController.cs

public class ErrorController : Controller
{

    private IHttpContextAccessor _context;

    public ErrorController(IHttpContextAccessor context)
    {
        _context = context;
    }

    public IActionResult Index()
    {
        return View();
    }

    public IActionResult Error()
    {
        var context = HttpContext.Features.Get<IExceptionHandlerFeature>();

        var exception = context.Error;

        var statusCode = HttpContext.Response.StatusCode;
        var message = context.Error.Message;
        var stackTrace = context.Error.StackTrace;

        return View(new ErrorViewModel { StatusCode = statusCode });
    }


    [AllowAnonymous]
    public IActionResult StatusCode(int? Id)
    {
        //var exceptionDetails = _context.HttpContext.Features.Get<IExceptionHandlerPathFeature>();

        if (Id.HasValue && Id != null)
        {
            if (Id == 404 || Id == 500 || Id == 403)
            {
                var viewName = Id.ToString();

                return View("StatusCode", new ErrorViewModel { ErrorCode = Id.ToString() });
            }
        }

        return View();
    }
}

When I trigger an exception e.g. accessing http://localhost/Error/Error, which invokes the Error action in the Error Controller, but it returnes null to the object:

var context = HttpContext.Features.Get<IExceptionHandlerFeature>();

thus I couldn't get any useful information I want from the page for troubleshooting later. Is there something I did wrong in this method?

If I trigger a HTTP 403 by accessing some resource the current user does not have acces to e.g. http://localhost/Requests/Details/123, it returns a view like:

return new ForbidResult();

which invokes the StatusCode action in Error Controller, but the only information I could get is the Id variable passed in which is the status code 403.

And if I try to access some resource doesn't exist e.g. http://localhost/Ghost, it will also go to the StatusCode action in Error Controller with a code 404.

It seems by using UseStatusCodePagesWithRedirects, it would fit better to what I want to achieve. But I am wondering is there anyway I could retrieve more application related information to return to the view or write into event log instead of just a genertic message with Http status code?

Thanks.

I am trying to implement a simple custom error handling page, after went through different approaches online, I have the following code:

Statup.cs

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{       
    app.UseExceptionHandler("/Error");

    app.UseStaticFiles();

    app.UseAuthentication();

    app.UseStatusCodePagesWithRedirects("/Error/StatusCode/{0}");

    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
        endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}/{id?}");
    });
}

ErrorController.cs

public class ErrorController : Controller
{

    private IHttpContextAccessor _context;

    public ErrorController(IHttpContextAccessor context)
    {
        _context = context;
    }

    public IActionResult Index()
    {
        return View();
    }

    public IActionResult Error()
    {
        var context = HttpContext.Features.Get<IExceptionHandlerFeature>();

        var exception = context.Error;

        var statusCode = HttpContext.Response.StatusCode;
        var message = context.Error.Message;
        var stackTrace = context.Error.StackTrace;

        return View(new ErrorViewModel { StatusCode = statusCode });
    }


    [AllowAnonymous]
    public IActionResult StatusCode(int? Id)
    {
        //var exceptionDetails = _context.HttpContext.Features.Get<IExceptionHandlerPathFeature>();

        if (Id.HasValue && Id != null)
        {
            if (Id == 404 || Id == 500 || Id == 403)
            {
                var viewName = Id.ToString();

                return View("StatusCode", new ErrorViewModel { ErrorCode = Id.ToString() });
            }
        }

        return View();
    }
}

When I trigger an exception e.g. accessing http://localhost/Error/Error, which invokes the Error action in the Error Controller, but it returnes null to the object:

var context = HttpContext.Features.Get<IExceptionHandlerFeature>();

thus I couldn't get any useful information I want from the page for troubleshooting later. Is there something I did wrong in this method?

If I trigger a HTTP 403 by accessing some resource the current user does not have acces to e.g. http://localhost/Requests/Details/123, it returns a view like:

return new ForbidResult();

which invokes the StatusCode action in Error Controller, but the only information I could get is the Id variable passed in which is the status code 403.

And if I try to access some resource doesn't exist e.g. http://localhost/Ghost, it will also go to the StatusCode action in Error Controller with a code 404.

It seems by using UseStatusCodePagesWithRedirects, it would fit better to what I want to achieve. But I am wondering is there anyway I could retrieve more application related information to return to the view or write into event log instead of just a genertic message with Http status code?

Thanks.

• asp-core
• -core
• asp-authorization
• custom-error-handling

1 Answer 1

If you need more details (such as the original URL or query parameters), consider using UseStatusCodePagesWithReExecute instead of UseStatusCodePagesWithRedirects:

app.UseStatusCodePagesWithReExecute("/Error/StatusCode/{0}");

Then, in your error action, you can retrieve additional information using:

var statusCodeReExecuteFeature = HttpContext.Features.Get<IStatusCodeReExecuteFeature>();

This feature provides properties like OriginalPath and OriginalQueryString, which can be useful for logging or for providing more context on your error page.