ASP NET MVC Custom Error Handling Application Error Global asax

Question

I have some basic code to determine errors in my MVC application  Currently in my project I have a controller called Error with action methods HTTPError404    HTTPError500    and General     They all accept a string parameter error  Using or modifying the code below  What is the best proper way to pass the data to the Error controller for processing  I would like to have a solution as robust as possible   protected void Application Error object sender  EventArgs e        Exception exception   Server GetLastError        Response Clear         HttpException httpException   exception as HttpException      if  httpException    null                RouteData routeData   new RouteData            routeData Values Add  controller    Error            switch  httpException GetHttpCode                          case 404                     page not found                 routeData Values Add  action    HttpError404                    break              case 500                     server error                 routeData Values Add  action    HttpError500                    break              default                  routeData Values Add  action    General                    break                    routeData Values Add  error   exception              clear error on server         Server ClearError                at this point how to properly pass route data to error controller

User · Answer

I have problem with this error handling approach: In case of web.config:

<customErrors mode="On"/>

The error handler is searching view Error.shtml and the control flow step in to Application_Error global.asax only after exception

System.InvalidOperationException: The view 'Error' or its master was not found or no view engine supports the searched locations. The following locations were searched: ~/Views/home/Error.aspx ~/Views/home/Error.ascx ~/Views/Shared/Error.aspx ~/Views/Shared/Error.ascx ~/Views/home/Error.cshtml ~/Views/home/Error.vbhtml ~/Views/Shared/Error.cshtml ~/Views/Shared/Error.vbhtml at System.Web.Mvc.ViewResult.FindView(ControllerContext context) ....................

So

 Exception exception = Server.GetLastError();
  Response.Clear();
  HttpException httpException = exception as HttpException;

httpException is always null then customErrors mode="On" :( It is misleading Then <customErrors mode="Off"/> or <customErrors mode="RemoteOnly"/> the users see customErrors html, Then customErrors mode="On" this code is wrong too

Another problem of this code that

Response.Redirect(String.Format("~/Error/{0}/?message={1}", action, exception.Message));

Return page with code 302 instead real error code(402,403 etc)

User · Answer

Use Following code for redirecting on route page  Use exception Message instide of exception  Coz exception query string gives error if it extends the querystring length   routeData Values Add  error   exception Message      clear error on server Server ClearError    Response RedirectToRoute routeData Values

User · Answer

I found a solution for ajax issue noted by Lion cl   global asax   protected void Application Error                            if  HttpContext Current Request IsAjaxRequest                          HttpContext ctx   HttpContext Current              ctx Response Clear                RequestContext rc     MvcHandler ctx CurrentHandler  RequestContext              rc RouteData Values  action      AjaxGlobalError                   TODO  distinguish between 404 and other errors if needed             rc RouteData Values  newActionName      WrongRequest                rc RouteData Values  controller      ErrorPages               IControllerFactory factory   ControllerBuilder Current GetControllerFactory                IController controller   factory CreateController rc   ErrorPages                controller Execute rc               ctx Server ClearError                      ErrorPagesController  public ActionResult AjaxGlobalError string newActionName                return new AjaxRedirectResult Url Action newActionName   this ControllerContext           AjaxRedirectResult  public class AjaxRedirectResult   RedirectResult       public AjaxRedirectResult string url  ControllerContext controllerContext            base url                ExecuteResult controllerContext              public override void ExecuteResult ControllerContext context                if  context RequestContext HttpContext Request IsAjaxRequest                          JavaScriptResult result   new JavaScriptResult                                 Script    try history pushState null null window location href   catch err   window location replace      UrlHelper GenerateContentUrl this Url  context HttpContext                                      result ExecuteResult context                     else                       base ExecuteResult context                       AjaxRequestExtension  public static class AjaxRequestExtension       public static bool IsAjaxRequest this HttpRequest request                return  request Headers  X-Requested-With      null  amp  amp  request Headers  X-Requested-With       XMLHttpRequest

User · Answer

Application Error having issue with Ajax requests  If error handled in Action which called by Ajax - it will display your Error View inside the resulting container

User · Answer

I struggled with the idea of centralizing a global error handling routine in an MVC app before  I have a post on the ASP NET forums   It basically handles all your application errors in the global asax without the need for an error controller  decorating with the  HandlerError  attribute  or fiddling with the customErrors node in the web config

User · Answer

Instead of creating a new route for that  you could just redirect to your controller action and pass the information via querystring  For instance   protected void Application Error object sender  EventArgs e      Exception exception   Server GetLastError      Response Clear       HttpException httpException   exception as HttpException     if  httpException    null        string action       switch  httpException GetHttpCode            case 404             page not found         action    HttpError404           break        case 500             server error         action    HttpError500           break        default          action    General           break                    clear error on server       Server ClearError           Response Redirect String Format    Error  0   message  1    action  exception Message            Then your controller will receive whatever you want      GET   Error HttpError404 public ActionResult HttpError404 string message       return View  SomeView   message       There are some tradeoffs with your approach  Be very very careful with looping in this kind of error handling  Other thing is that since you are going through the asp net pipeline to handle a 404  you will create a session object for all those hits  This can be an issue  performance  for heavily used systems

User · Answer

To answer the initial question  how to properly pass routedata to error controller     IController errorController   new ErrorController    errorController Execute new RequestContext new HttpContextWrapper Context   routeData      Then in your ErrorController class  implement a function like this    AcceptVerbs HttpVerbs Get   public ViewResult Error Exception exception        return View  Error   exception       This pushes the exception into the View  The view page should be declared as follows    lt    Page Language  C   Inherits  System Web Mvc ViewPage lt System Exception gt     gt    And the code to display the error    lt   if Model    null      gt    lt p gt  lt b gt Detailed error  lt  b gt  lt br   gt    lt span class  error  gt  lt    Helpers General GetErrorMessage  Exception Model  false    gt  lt  span gt  lt  p gt   lt       gt    Here is the function that gathers the all exception messages from the exception tree       public static string GetErrorMessage Exception ex  bool includeStackTrace                StringBuilder msg   new StringBuilder            BuildErrorMessage ex  ref msg           if  includeStackTrace                        msg Append   n                msg Append ex StackTrace                     return msg ToString               private static void BuildErrorMessage Exception ex  ref StringBuilder msg                if  ex    null                        msg Append ex Message               msg Append   n                if  ex InnerException    null                                BuildErrorMessage ex InnerException  ref msg

User · Answer

Brian  This approach works great for non-Ajax requests  but as Lion cl stated  if you have an error during an Ajax call  your Share Error aspx view  or your custom error page view  will be returned to the Ajax caller--the user will NOT be redirected to the error page

User · Answer

This may not be the best way for MVC   https   stackoverflow com a 9461386 5869805    Below is how you render a view in Application Error and write it to http response  You do not need to use redirect  This will prevent a second request to server  so the link in browser s address bar will stay same  This may be good or bad  it depends on what you want   Global asax cs  protected void Application Error         var exception   Server GetLastError           TODO do whatever you want with exception  such as logging  set errorMessage  etc      var errorMessage    SOME FRIENDLY MESSAGE           TODO  UPDATE BELOW FOUR PARAMETERS ACCORDING TO YOUR ERROR HANDLING ACTION     var errorArea    AREA       var errorController    CONTROLLER       var errorAction    ACTION       var pathToViewFile       Areas  errorArea  Views  errorController   errorAction  cshtml      THIS SHOULD BE THE PATH IN FILESYSTEM RELATIVE TO WHERE YOUR CSPROJ FILE IS       var requestControllerName   Convert ToString HttpContext Current Request RequestContext  RouteData  Values  controller         var requestActionName   Convert ToString HttpContext Current Request RequestContext  RouteData  Values  action          var controller   new BaseController       REPLACE THIS WITH YOUR BASE CONTROLLER CLASS     var routeData   new RouteData   DataTokens        area   errorArea      Values        controller   errorController      action   errorAction           var controllerContext   new ControllerContext new HttpContextWrapper HttpContext Current   routeData  controller       controller ControllerContext   controllerContext       var sw   new StringWriter        var razorView   new RazorView controller ControllerContext  pathToViewFile      false  null       var model   new ViewDataDictionary new HandleErrorInfo exception  requestControllerName  requestActionName        var viewContext   new ViewContext controller ControllerContext  razorView  model  new TempDataDictionary    sw       viewContext ViewBag ErrorMessage   errorMessage        TODO  add to ViewBag what you need     razorView Render viewContext  sw       HttpContext Current Response Write sw       Server ClearError        HttpContext Current Response End       No more processing needed  ex  by default controller action routing   flush the response out and raise EndRequest event      View   model HandleErrorInfo        ViewBag Title    Error          TODO  SET YOUR LAYOUT    lt div class    gt      ViewBag ErrorMessage  lt  div gt   if Model    null  amp  amp  HttpContext Current IsDebuggingEnabled         lt div class    style  background khaki  gt           lt p gt               lt b gt Exception  lt  b gt   Model Exception Message  lt br  gt               lt b gt Controller  lt  b gt   Model ControllerName  lt br  gt               lt b gt Action  lt  b gt   Model ActionName  lt br  gt           lt  p gt           lt div gt               lt pre gt                   Model Exception StackTrace              lt  pre gt           lt  div gt       lt  div gt

User · Answer

Perhaps a better way of handling errors in MVC is to apply the HandleError attribute to your controller or action and update the Shared Error aspx file to do what you want  The Model object on that page includes an Exception property as well as ControllerName and ActionName

[c#] ASP.NET MVC Custom Error Handling Application_Error Global.asax?

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