How to display my 404 page in Nancy?

Question

I need to display my 404 error page in Nancy like this

if (ErrorCode == 404)
{
  return View["404.html"];
}

How to do it?

Answer 1

The answer from nemesv is correct, but I just wanted to add an example using the ViewRenderer instead of the GenericFileResponse.

public class MyStatusHandler : IStatusCodeHandler
{
    private IViewRenderer viewRenderer;

    public MyStatusHandler(IViewRenderer viewRenderer)
    {
        this.viewRenderer = viewRenderer;
    }

    public bool HandlesStatusCode(HttpStatusCode statusCode,
                                  NancyContext context)
    {
        return statusCode == HttpStatusCode.NotFound;
    }

    public void Handle(HttpStatusCode statusCode, NancyContext context)
    {
        var response = viewRenderer.RenderView(context, "/status/404");
        response.StatusCode = statusCode;
        context.Response = response;
    }
}

Answer 2

You just need to provide an implementation of the IStatusCodeHandler interface (it will be picked up automatically by Nancy).

In the HandlesStatusCode method return true for the HttpStatusCode.NotFound.

And in the Handle method you need to set the Response property on the NancyContext with a response containing your error page content. You can use for example the GenericFileResponse:

public class My404Hander : IStatusCodeHandler
{
    public bool HandlesStatusCode(HttpStatusCode statusCode, 
                                  NancyContext context)
    {
        return statusCode == HttpStatusCode.NotFound;
    }

    public void Handle(HttpStatusCode statusCode, NancyContext context)
    {
        var response = new GenericFileResponse("404.html", "text/html");
        response.StatusCode = statusCode;
        context.Response = response;            
    }
}