Gaurav123 Gaurav123 - 3 months ago 11
C# Question

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

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
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"/>
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