private async Task ExportFile(string download_path, string filename)
 {
     await QueuedTask.Run(async() => {
         try
         {
             Geodatabase gdb     = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri(@download_path)));
             string default_path = Path.GetDirectoryName(Project.Current.URI);
             await DownloadFile(default_path, filename);
             string fullPath       = Path.Combine(default_path, filename);
             string rasterFileName = Path.GetFileNameWithoutExtension(fullPath);
             string rasterName     = Regex.Replace(rasterFileName, @"[^0-9a-zA-Z_]", "_"); //string.Empty
             string outputRaster   = Path.Combine(download_path, rasterName);
             await Ag_Analytics_Module.CopyRaster(fullPath, outputRaster);
             await Ag_Analytics_Module.SetToStretchColorizerFromLayerName(rasterFileName, "Elevation #10");
             // delete files in default path
             File.Delete(fullPath);
         }
         catch
         {
             await DownloadFile(download_path, filename);
             await Ag_Analytics_Module.AddLayerToMapAsync(Path.Combine(download_path, filename));
             await Ag_Analytics_Module.SetToStretchColorizerFromLayerName(filename, "Elevation #10");
         }
     });
 }