Global Exception Handling with Web API 2

Question

I’m willing to use the Global Error Handling with Webapi 2.

I created a new project, within it I created the following class:

Errologteste.Cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Web;
using System.Web.Http.ExceptionHandling;

namespace ApiTesteErro
{
    public class ErroLogTeste : ExceptionLogger
    {
        public override void Log(ExceptionLoggerContext context)
        {
            Trace.TraceError(context.ExceptionContext.Exception.ToString());
        }
    }
}

Then I changed the remote Home as follows:

Homecontroller.Cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace ApiTesteErro.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            ViewBag.Title = "Home Page";

            int x;
            var a = "j";

            x = Convert.ToInt16( a);

            return View();
        }
    }
}

I added the service in Webapiconfig:

Webapiconfig.Cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;
using System.Web.Http.ExceptionHandling;

namespace ApiTesteErro
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services
            GlobalConfiguration.Configuration.Services.Add(typeof(IExceptionLogger), new ErroLogTeste());

            // Web API routes
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }
    }
}

I also tried with config.Services.Add(typeof(IExceptionLogger), new ErroLogTeste()); and it didn’t work

When I turn, he misses the x = Convert.ToInt16( a);, but does nothing in my class ErroLogTeste.

What else do I need to do for him to run the log?

Answer 1

You should register like this:

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        config.Services.Add(typeof(IExceptionLogger), new ErroLogTeste());

        ...
    }
}

As you didn’t mention anything, I believe it was missing set up trace listeners. Simply call Trace.TraceError does not register anywhere by default.

Answer 2

Add this here after registering routes.

It’ll stay that way

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;
using System.Web.Http.ExceptionHandling;

namespace ApiTesteErro
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services
            GlobalConfiguration.Configuration.Services.Add(typeof(IExceptionLogger), new ErroLogTeste());

            // Web API routes
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
            config.Filters.Add(new ExceptionHandlingAttribute()); 
        }
    }
}