Force MapKit use cached map tiles only/disable net

问题:

We have stumbled upon such a problem.

We are developing an application for travelling. To make sure the user doesn't spend much money on roaming charges in our app we decided to implement a settings option for user to view cached maps only. So we let the user decide whether he wants to load the maps from internet or he wants to save money and view cached maps (stored in Library/Caches/MapTiles/MapTiles.sqlitedb).

We can't find a way to implement this. Is there any way to disable network programmatically in this case? Or force MapKit use cached tiles only? We thought about changing APN programmatically for this option to force MapKit go offline. Is it possible to change APN programmatically?

Thank you!

回答1:

iPhone SDK apps do not have access to the network adapter settings, and I know of nothing in the MapKit API that gives you control over its Internet usage. Your best option in this case is probably to present an alert suggesting that the user enable Airplane Mode or turn off data roaming.

回答2:

use openstreetmap think the commercial side of it Cloud-made allows offline maps

http://developers.cloudmade.com/projects/show/iphone-sdk

Libraries that help iPhone developers use OSM maps route-me is an open-source library used in a number of iPhone applications to display OSM maps. The CloudMade iPhone Maps Library is an open-source library that provides high-level access to CloudMade's OSM-based map tiles with different sizes and different styles. John McKerrell has ported the routing algorithm from gosmore to run on the iPhone and has successfully generated basic routes. More complicated routes crash the iPhone at the moment

回答3:

There are some ways. One is to use your own tile overlay and implement the caching algorithm either in URLForTilePath: or in loadTileAtPath:result:

It works very well with open domain and some private ones. Does not cache the standard Apple Maps.

Another way that will be able to cache everything is subclass NSURLProtocol. There are some tutorials and probably you may detect when is a map image and act accordingly

回答4:

the google map app does the cache feature ... MapKit seem no , I think Apple will add this feature in next version SDK ...