How to retrieve images from cache memory in picass

问题:

I am using picasso library for loading images .In default picasso, It uses internal cache memory for loading images.But as per my app configuration ,i have to use external cache memory(Cache on Disk). so i used this code for Cache on Disk

              File httpCacheDir = new File(getApplicationContext().getExternalCacheDir(),"http");
                long httpCacheSize = 10 * 1024 * 1024; // 10 MiB
               HttpResponseCache.install(httpCacheDir, httpCacheSize);}

Picasso is flexible. So now it caches images in external Sd card..

The caches is stored in sdcard/android/data/packagename/cache/http The caches are stored in ".1" ,".0". formats so i just opened them and changes into ".1" to ".jpg".it gives exact images what i need. But how to do in programatically? but picasso itself caches my memory in to my app for loading image into imageview.but i have to save them into sdcard directly as images/set bitmap as wallpaper in offline mode?

回答1:

You can supply your own Cache implementation when building your Picasso instance. This way you can provide extra methods that you can call to retrieve bitmaps directly from your memory cache. Use Picasso.Builder to provide your own implementation for it. When you use with() you are using a static singleton internal instance thats setup with most of the default values (most apps need the default values anyway.)

Keep a reference of your Cache implementation around and directly interact with it. Picasso is meant to handle the loading/decoding and caching for you but there is no reason you cant build around it.

If you are referring about the disk cache, then no Picasso does not support that at the moment. This is by design because the disk layer cache is done by the HTTP layer and makes no distinction about it.

You could however, change the path of the disk cache. If you are using OkHttpDownloader then supply a different file when you construct your Downloader. Similarly for UrlConnectionDownloader you could extend it and override the load() method.

回答2:

Picasso does handle the caching in it and downloading also you just need to place it in your target Image view similar to Aquery

According to The Corner Square Engineering blog picasso handle downloading caching in it self and give its handler to user to use it and place the image in image view