How to pass error message to error view in MVC 5?

Question

I am working on exception handling and have written below code for the same.

Web.Config

<customErrors mode="On"></customErrors>

Code Changes

public class CustomExceptionFilter : HandleErrorAttribute
{
    public override void OnException(ExceptionContext filterContext)
    {

        //_logger.Error("Uncaught exception", filterContext.Exception);

        ViewResult view = new ViewResult();
        view.ViewName = "Error";
        filterContext.Result = view;

        // Prepare the response code.
        filterContext.ExceptionHandled = true;
        filterContext.HttpContext.Response.Clear();
        filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;
    }
}

Global.asax

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);

    // To handle exceptions
    GlobalFilters.Filters.Add(new CustomExceptionFilter());

    var unityContainer = ModelContainer.Instance;
    DependencyResolver.SetResolver(new UnityDependencyResolver(unityContainer));
}

Error View

@*@model System.Web.Mvc.HandleErrorAttribute*@
<div class="row">
    <div class="col-sm-12">
        <h1>Error</h1>
        <div class="col-sm-12">
            <h2>An error occurred while processing your request.</h2>
        </div>
    </div>
</div>

In my error view, I want to show the exception message.

Also I have one more requirement to show different message in case of 404 error exists.

Answer 1

public class CustomExceptionFilter : HandleErrorAttribute {
    public override void OnException(ExceptionContext filterContext) {

        var controller = filterContext.Controller as Controller;
        controller.Response.StatusCode = (int)System.Net.HttpStatusCode.InternalServerError;
        controller.Response.TrySkipIisCustomErrors = true;
        filterContext.ExceptionHandled = true;

        var controllerName = (string)filterContext.RouteData.Values["controller"];
        var actionName = (string)filterContext.RouteData.Values["action"];
        var exception = filterContext.Exception;
        //need a model to pass exception data to error view
        var model = new HandleErrorInfo(exception, controllerName, actionName);

        var view = new ViewResult();
        view.ViewName = "Error";
        view.ViewData = new ViewDataDictionary();
        view.ViewData.Model = model;

        //copy any view data from original control over to error view
        //so they can be accessible.
        var viewData = controller.ViewData;
        if (viewData != null && viewData.Count > 0) {
            viewData.ToList().ForEach(view.ViewData.Add);
        }

        //Instead of this
        ////filterContext.Result = view;
        //Allow the error view to display on the same URL the error occurred
        view.ExecuteResult(filterContext);

        //should do any logging after view has already been rendered for improved performance.
        //_logger.Error("Uncaught exception", exception);

    }
}

Views/Shared/Error.cshtml

@model System.Web.Mvc.HandleErrorInfo
@{
    ViewBag.Title = "Error";
}
<div class="row">
    <div class="col-sm-12">
        <h1>Error</h1>
        <div class="col-sm-12">
            <h2>An error occurred while processing your request.</h2>
        </div>
        <div>
            @{
                if (Model != null && Model.Exception != null) {
                    <h5>Here is some information you can pass on to the administrator</h5>
                    <h3>Path: ~/@string.Format("{0}/{1}", Model.ControllerName, Model.ActionName)</h3>
                    <h4>Error: @Model.Exception.GetType().Name</h4>
                    if (Request.IsLocal) {
                        <h4>Message: @Model.Exception.Message</h4>
                        <h5>@Model.Exception.StackTrace</h5>
                    }
                }
            }
        </div>
    </div>
</div>

Web.Config

<customErrors mode="Off"/>

Answer 2

You can try sending like this

filterContext.HttpContext.Items["Exception"] = Exception.Message;