I am making an attempt to build the most efficient way of caching images downloaded from the web for my app, a few years ago I tried to do this and could not find an efficient method of making this work until I stumbled upon the lazylist adapter found here:
Lazy load of images in ListView
this worked well until android 4.0 was introduced, at this point the app would crash after loading 10 to 20 images, as opposed to before where I could simply load up as many as I wanted without any issues, this I later found out was a result of the Ice cream sandwich having a set limit on memory usage per app, which didnt exist in Gingerbread 2.3 and below, I eventually decided to just clear the cache every 10 or so images to avoid crashing, however the user experience wasn't very good as a result of doing this and the app used tons of data as it was constantly redownloading images over and over again that were already viewed, I have since attempted to use an lru cache but this does not seem to work at all, especially when I leave the app and relaunch it the images are all released it seems, I need a better way of doing this and I have noticed that other apps such as instagram seem to have found a way to cache hundreds of megabytes of images, Im consistently having to manually clear the instagram cache in my settings because it seems that they are to able to store an infinite sized cache that seeming never ejects its contents, does anyone know how to build this kind of cache?
You can try using https://github.com/nostra13/Android-Universal-Image-Loader library. This does most of the hardwork for you.