You could use the WebTiledLayer as described in the Notes section of the Description - WebTiledLayer Class | ArcGIS for Developers
Note: This layer requires a string as opposed to a URL, which is the required data format for most other layers. Use "http://" to reference an online layer and use the file path to a local tile cache when working with an offline layer (do not add the "file:///" prefix). For example, use "C:/dataPath/{level}/{column}/{row}.png" and not "file:///C:/dataPath/{level}/{column}/{row}.png"
