How pass the TempData in ExceptionFilterAttribute in Asp.Net Core

Question

I have tried to create the Exception filter for my controller in Asp.Net Core MVC like this:

public class ControllerExceptionFilterAttribute : ExceptionFilterAttribute
{
    private readonly IHostingEnvironment _hostingEnvironment;

    public ControllerExceptionFilterAttribute(
        IHostingEnvironment hostingEnvironment)
    {
        _hostingEnvironment = hostingEnvironment;
    }

    public override void OnException(ExceptionContext context)
    {
        //How construct a temp data here which I want to pass to error page?
        var result = new ViewResult
        {
            ViewName = "Error"
        };

        context.ExceptionHandled = true; // mark exception as handled
        context.Result = result;
    }
}

I need in OnException method work with TempData - how can I set some exception information to TempData in this place? I have used this TempData to some notification.

There is missing something like this: context.Controller.TempData["notification"] - Controller property was probable removed.

Answer 1

You can achieve what you're looking for with the ITempDataDictionaryFactory , which you can take into your constructor via dependency injection. This has a single function, GetTempData , which can be used for accessing what you refer to as TempData . Here's a complete example to suit your needs:

public class ControllerExceptionFilterAttribute : ExceptionFilterAttribute
{
    private readonly IHostingEnvironment _hostingEnvironment;
    private readonly ITempDataDictionaryFactory _tempDataDictionaryFactory;

    public ControllerExceptionFilterAttribute(
        IHostingEnvironment hostingEnvironment,
        ITempDataDictionaryFactory tempDataDictionaryFactory)
    {
        _hostingEnvironment = hostingEnvironment;
        _tempDataDictionaryFactory = tempDataDictionaryFactory;
    }

    public override void OnException(ExceptionContext context)
    {
        //How construct a temp data here which I want to pass to error page?
        var tempData = _tempDataDictionaryFactory.GetTempData(context.HttpContext);

        var result = new ViewResult
        {
            ViewName = "Error"
        };

        context.ExceptionHandled = true; // mark exception as handled
        context.Result = result;
    }
}