How can I return a ContentResult and a FileResult in the same method?

Question

I am working with MVC and I have the next methos which return a ContentResult, and in the same method I need to download a FileResult, the problem is the excel is downloaded with no notify the user on the browser:

    [HttpPost]
    public ActionResult SetReportId()
    {

        //Some code
        var report = reportView.Report;
        var reportName = report.Name;
        if (!reportView.HasReportPreview)
        {
            var fileName = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) + 
@"\Downloads\" + string.Format("{0}.{1}", reportName, "xlsx");
            report.ExportToXlsx(fileName);
        }

        return new ContentResult
        {
            Content = iid.ToString(),
            ContentEncoding = Encoding.UTF8,
            ContentType = "text/plain"
        };
    }

However if I use this test method returning a FileResult the file is downloaded with a 
notification on the browser:



 [MvcPermissionAuthorizationFilter("Reports|1")]
            [QueryLoginHandlingFilter]
            public ActionResult Report()
            {
               //Some code
                var rep = reportView.Report;
                var fileName = String.Format("Report.{0}", "xlsx");
    
                 using (MemoryStream ms = new MemoryStream())
                {
                  rep.ExportToXlsx(ms);
                  return ExportDocument(ms.ToArray(), "xlsx", fileName, false);
                }
            }

The problem is the method requires tu return a ContentResult, any hint in order to return 
ContentResult besides the FileResult in the same method.