public class MvcHandleErrorAttribute : HandleErrorAttribute
    {
        public override void OnException(ExceptionContext filterContext)
        {
            //这里可以做错误日志处理或写数据库等操作
            Console.WriteLine(filterContext.Exception.Message);
            base.OnException(filterContext);
        }
    }

public class FilterConfig
    {
        public static void RegisterGlobalFilters(GlobalFilterCollection filters)
        {
            //filters.Add(new HandleErrorAttribute());
            filters.Add(new MvcHandleErrorAttribute());
        }
    }

public class WebApiExceptionFilter : ExceptionFilterAttribute
    {
        public override void OnException(HttpActionExecutedContext context)
        {

            var message = context.Exception.Message;
            if (context.Exception.InnerException != null)
                message = context.Exception.InnerException.Message;

            context.Response = new HttpResponseMessage() { Content = new StringContent(message) };

            base.OnException(context);
        }
    }

public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            //是为了让WebApi的控制器自动匹配ApiController
            var suffix = typeof(DefaultHttpControllerSelector).GetField("ControllerSuffix", BindingFlags.Static | BindingFlags.Public);
            if (suffix != null) suffix.SetValue(null, "ApiController");

            //为了让WebApi也支持NameSpace
            config.Services.Replace(typeof(IHttpControllerSelector), new NamespaceHttpControllerSelector(config));

            //为WebApi添加过滤器
            config.Filters.Add(new WebApiExceptionFilter());

            // Web API 路由
            config.MapHttpAttributeRoutes();

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