public Envelope Extent {get; set;}

//namespace ArcGIS.Desktop.Mapping.Offline
var extent = MapView.Active.Extent;
var map = MapView.Active.Map;

//await if needed...
QueuedTask.Run(() =>
{
  //Does the map have any exportable raster content?
  var canExport = GenerateOfflineMap.Instance.GetCanExportRasterTileCache(map);
  if (canExport)
  {
    //Check the available LOD scale ranges
    var scales = GenerateOfflineMap.Instance.GetExportRasterTileCacheScales(map, extent);
    //Pick the desired LOD scale
    var max_scale = scales[scales.Count() / 2];

    //Configure the export parameters
    var export_params = new ExportTileCacheParams()
    {
      Extent = extent,//Use same extent as was used to retrieve scales
      MaximumUserDefinedScale = max_scale
      //DestinationFolder = .... (optional)
    };
    //If DestinationFolder is not set, output defaults to project
    //offline maps location set in the project properties. If that is 
    //not set, output defaults to the current project folder location.

    //Do the export. Depending on the MaximumUserDefinedScale and the
    //area of the extent requested, this can take minutes for tile packages
    //over 1 GB or less if your network speed is slow...
    GenerateOfflineMap.Instance.ExportRasterTileCache(map, export_params);
  }
});

//namespace ArcGIS.Desktop.Mapping.Offline
var extent = MapView.Active.Extent;
var map = MapView.Active.Map;

//await if needed...
QueuedTask.Run(() =>
{
  //Does the map have any exportable vector tile content?
  var canExport = GenerateOfflineMap.Instance.GetCanExportVectorTileCache(map);
  if (canExport)
  {
    //Check the available LOD scale ranges
    var scales = GenerateOfflineMap.Instance.GetExportVectorTileCacheScales(map, extent);
    //Pick the desired LOD scale
    var max_scale = scales[scales.Count() / 2];

    //Configure the export parameters
    var export_params = new ExportTileCacheParams()
    {
      Extent = extent,//Use same extent as was used to retrieve scales
      MaximumUserDefinedScale = max_scale,
      DestinationFolder = @"C:\Data\Offline"
    };
    //If DestinationFolder is not set, output defaults to project
    //offline maps location set in the project properties. If that is 
    //not set, output defaults to the current project folder location.

    //Do the export. Depending on the MaximumUserDefinedScale and the
    //area of the extent requested, this can take minutes for tile packages
    //over 1 GB or less if your network speed is slow...
    GenerateOfflineMap.Instance.ExportVectorTileCache(map, export_params);
  }
});