TileCache Class

Detailed Description

Functional characteristics

A tile cache stores a collection of images at various scales. A client can request the tiles needed to display a particular map extent. You can use ExportTileCacheTask to generate and download tiles from a service, thereby creating a tile package (.tpk/.tpkx). Alternatively, you can use ArcGIS Pro to create a map tile package and provision it to the device. ArcGIS tiled layers do not support reprojection, query, select, identify, or editing.

Performance characteristics

Tiles are generated when the cache is created. Requests for tiles are made on multiple threads and handled asynchronously. The size of each returned tile increases as the resolution or complexity of the image in the tile increases. For example, high-resolution imagery tiles can be larger files than topographic mapping for the same area and map extent.

Local tile caches are ideal for providing basemaps, or for infrequent changes to contextual layers when network access is limited or non-existent. Use ExportTileCacheJob to create and download a local tile cache to a device. Alternatively, the cache can be provisioned directly to local storage. The supported types of cache file formats are:

• Tile package (.tpk, .tpkx) - a tile cache of data, packaged into one convenient, portable file, ideal for offline sharing of complete tiled layers in a disconnected environment or via a portal.
• Compact Cache - a directory structure where groups of tiles are combined into larger .bundle files, preserving performance and reducing copy times and the size on disk of the cache.
• Exploded Cache - a directory structure where map tiles are stored as individual files.

A TileCache is often used as a basemap, but can also be used to create an ArcGISTiledLayer that is added to a map as an operational layer. An offline ArcGISTiledElevationSource can also be created from an appropriate tile cache and added to the Scene::baseSurface of a Scene.