title: Warning message in async method saying that it lacks await operators
body: <p>I have a excel download in my asp.net mvc 4 application. When I click the export button the below controller method gets called. Since I need it to be done asynchronous, I am using  async and await here.</p>
  
  <pre><code>public async Task&lt;ActionResult&gt; GenerateReportExcel()
      {
          ExcelGenerator excel = new ExcelGenerator();
          var filePath = await excel.ReportExcelAsync(midyearReportViewModel);
          System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
          response.ClearContent();
          response.Clear();
          response.ContentType = "text/plain";
          response.AddHeader("Content-Disposition", string.Format("attachment;filename={0}.xlsx;", PdaResource.ReportFileName)); 
          response.TransmitFile(filePath);
          response.Flush();
          response.End();
          return PartialView("_MidYearReportPartial", midyearReportViewModel);
      }
  </code></pre>
  
  <p>This method inturn call a excel generator method ReportExcelAsync as shown below</p>
  
  <pre><code>public async Task&lt;string&gt; ReportExcelAsync(MidYearReportViewModel _midyearAnnualviewModel)
      {
          string fileName = "MidYearReport";
          string finalXcelPath = string.Empty;
          string currentDirectorypath = new DirectoryInfo(HttpContext.Current.Server.MapPath("~/Export")).ToString();
          finalXcelPath = string.Format("{0}\\{1}.xlsx", currentDirectorypath, fileName);
          if (System.IO.File.Exists(finalXcelPath))
          {
              System.IO.File.Delete(finalXcelPath);
          }
          var newFile = new FileInfo(finalXcelPath);
          using (ResXResourceSet resxSet = new ResXResourceSet(resxFile))
          {
              using (var package = new ExcelPackage(newFile))
              {
                  ExcelWorksheet worksheet = package.Workbook.Worksheets.Add(resxSet.GetString("ReportMYMidYearExcelSheetName"));
                  for (int i = 1; i &lt;= header.Count(); i++)
                  {
                      worksheet.Cells[1, i].Value = header[i - 1];
                      worksheet.Cells[1, i].Style.Font.Bold = true;
                      worksheet.Cells[1, i].Style.Fill.PatternType = ExcelFillStyle.Solid;
                      worksheet.Cells[1, i].Style.Font.Color.SetColor(Color.White);
                      worksheet.Cells[1, i].Style.Fill.BackgroundColor.SetColor(Color.DimGray);
                  }
                  package.Save();
              }
          }
          return finalXcelPath; 
      }
  </code></pre>
  
  <p>But I get a warning message as Warning </p>
  
  <blockquote>
    <p>This async method lacks 'await' operators and will run synchronously.
    Consider using the 'await' operator to await non-blocking API calls,
    or 'await Task.Run(...)' to do CPU-bound work on a background thread</p>
  </blockquote>
  
  <p>. Am I doing something wrong ?.My code works fine and I am able to get the excel downloaded. </p>