public T OpenDataset<T>( 
   string name
)
where T: Dataset

public async Task OpenTinDataset()
{
  try
  {
    await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
    {
      string path = @"d:\Data\Tin";
      var fileConnection = new FileSystemConnectionPath(new Uri(path), FileSystemDatastoreType.Tin);

      using (FileSystemDatastore dataStore = new FileSystemDatastore(fileConnection))
      {
        // TIN is in a folder at d:\Data\Tin\TinDataset

        string dsName = "TinDataset";

        using (var dataset = dataStore.OpenDataset<ArcGIS.Core.Data.Analyst3D.TinDataset>(dsName))
        {

        }
      }
    });
  }
  catch (GeodatabaseNotFoundOrOpenedException exception)
  {
    // Handle Exception.
  }
}

public async Task OpenLasDataset()
{
  try
  {
    await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
    {
      string path = @"d:\Data\LASDataset";
      var fileConnection = new FileSystemConnectionPath(new Uri(path), FileSystemDatastoreType.LasDataset);

      using (FileSystemDatastore dataStore = new FileSystemDatastore(fileConnection))
      {
        string name = "utrecht_tile.lasd";      // can specify with or without the .lasd extension

        using (var dataset = dataStore.OpenDataset<ArcGIS.Core.Data.Analyst3D.LasDataset>(name))
        {

        }
      }
    });
  }
  catch (GeodatabaseNotFoundOrOpenedException exception)
  {
    // Handle Exception.
  }
}

public async Task OpenShapefileFeatureClass()
{
  await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
  {
    FileSystemConnectionPath fileConnection = new FileSystemConnectionPath(new Uri("path\\to\\folder\\containing\\shapefiles"), FileSystemDatastoreType.Shapefile);
    using (FileSystemDatastore shapefile = new FileSystemDatastore(fileConnection))
    {
      FeatureClass taxLotsFeatureClass = shapefile.OpenDataset<FeatureClass>("TaxLots");
      FeatureClass manHolesFeatureClass = shapefile.OpenDataset<FeatureClass>("ManHoles.shp"); // Can use the .shp extension, but its not needed.
      Table taxDetailsTableWithoutExtension = shapefile.OpenDataset<Table>("TaxDetails");
      Table taxDetailsTable = shapefile.OpenDataset<Table>("TaxDetails.dbf");
    }
  });
}

public async Task OpenCADFeatureClass()
{
  await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
  {
    FileSystemConnectionPath fileConnection = new FileSystemConnectionPath(new Uri("path\\to\\folder\\containing\\CAD"), FileSystemDatastoreType.Cad);
    using (FileSystemDatastore cadDatastore = new FileSystemDatastore(fileConnection))
    {
      // note - extension is required
      FeatureClass cadDataset = cadDatastore.OpenDataset<FeatureClass>("hatchplayboundaries.dwg");
      // take note of the pattern for referencing a feature class. 
      FeatureClass cadfeatureClass = cadDatastore.OpenDataset<FeatureClass>("hatchplayboundaries.dwg:Polyline");

      int numRows = 0;
      using (RowCursor cursor = cadfeatureClass.Search())
      {
        while (cursor.MoveNext())
          numRows++;
      }
    }
  });
}

// Create a FileSystemConnectionPath using the folder path.
FileSystemConnectionPath connectionPath = new FileSystemConnectionPath(new System.Uri(@"C:\Temp"), FileSystemDatastoreType.Raster);
// Create a new FileSystemDatastore using the FileSystemConnectionPath.
FileSystemDatastore dataStore = new FileSystemDatastore(connectionPath);
// Open the raster dataset.
RasterDataset fileRasterDataset = dataStore.OpenDataset<RasterDataset>("Sample.tif");