Catch 404 Error in MVC4

Question

I have an problem cacting the HTTP Error 404.0 - Not Found. I have turned on the

<customErrors mode="On" defaultRedirect="~/Error/General">
      <error statusCode="404" redirect="~/Error/HttpError404" />
      <error statusCode="500" redirect="~/Error/HttpError500" />
    </customErrors>

in the Web.Config. But the problem still exist. I have also tried this solution( But it never reaches the method):

protected void Application_Error()
    {
      var exception = Server.GetLastError();
      var httpException = exception as HttpException;
      Response.Clear();
      Server.ClearError();
      var routeData = new RouteData();
      routeData.Values["controller"] = "Errors";
      routeData.Values["action"] = "General";
      routeData.Values["exception"] = exception;
      Response.StatusCode = 500;
      if (httpException != null)
      {
        Response.StatusCode = httpException.GetHttpCode();
        switch (Response.StatusCode)
        {
          case 403:
            routeData.Values["action"] = "HttpError404";
            break;
          case 404:
            routeData.Values["action"] = "HttpError404";
            break;
        }
      }

      IController errorsController = new ErrorController();
      var rc = new RequestContext(new HttpContextWrapper(Context), routeData);
      errorsController.Execute(rc);
    }

provided by @Darin Dimitrov

This is the controller:

public class ErrorController : Controller
  {

    public ActionResult HttpError404(string error)
    {
      ViewData["Title"] = "Sorry, an error occurred while processing your request. (404)";
      ViewData["Description"] = error;
      return View("Index");
    }

    public ActionResult HttpError500(string error)
    {
      ViewData["Title"] = "Sorry, an error occurred while processing your request. (500)";
      ViewData["Description"] = error;
      return View("Index");
    }


    public ActionResult General(string error)
    {
      ViewData["Title"] = "Sorry, an error occurred while processing your request.";
      ViewData["Description"] = error;
      return this.View();

    }

Answer 1

Okay i found an solution thanks to @alistair-findlay and this website. This is how the web.config looks like now:

<system.web>
    <customErrors mode="On" defaultRedirect="~/Error/General" redirectMode="ResponseRewrite"> 
        </customErrors>
 </system.web>
  <system.webServer>
<httpErrors errorMode="Detailed" defaultResponseMode="Redirect">
      <clear/>
      <error statusCode="404" path="/Error/HttpError404"/>
    </httpErrors>

  </system.webServer

And this is the Global.asax.cs:

  protected void Application_Error()
    {

      if (Context.IsCustomErrorEnabled)
        ShowCustomErrorPage(Server.GetLastError());

    }
    private void ShowCustomErrorPage(Exception exception)
    {
      var httpException = exception as HttpException ?? new HttpException(500, "Internal Server Error", exception);

      Response.Clear();
      var routeData = new RouteData();
      routeData.Values.Add("controller", "Error");
      routeData.Values.Add("fromAppErrorEvent", true);

      switch (httpException.GetHttpCode())
      {
        case 403:
          routeData.Values.Add("action", "HttpError403");
          break;

        case 404:
          routeData.Values.Add("action", "HttpError404");
          break;

        case 500:
          routeData.Values.Add("action", "HttpError500");
          break;

        default:
          routeData.Values.Add("action", "GeneralError");
          routeData.Values.Add("httpStatusCode", httpException.GetHttpCode());
          break;
      }

      Server.ClearError();

      IController controller = new ErrorController();
      controller.Execute(new RequestContext(new HttpContextWrapper(Context), routeData));
    }

And lastly:

 public class ErrorController : Controller
  {

    public ActionResult HttpError403(string error)
    {
      ViewBag.Description = error;
      return this.View();
    }

Answer 2

Have you implemented an ErrorController that handles the redirects in your customErrors attributes? In your case, it would look something like this:

public class ErrorController : Controller
{
    public ActionResult General()
    {
        return View();
    }

    public ActionResult HttpError404()
    {
        return View();
    }

    public ActionResult HttpError500()
    {
        return View();
    }
}

You would also need to implement the views for each of the ActionResults in your Views folder.

In terms of logging the error, you would need to implement this in the Application_Error event handler as follows:

protected void Application_Error()
{
    var exception = Server.GetLastError();
    var httpException = exception as HttpException;
    // Do logging here
}

This is to "catch" the error before the 302 redirect to your Error pages defined in the ErrorController above.