I'm using fedor's lazy loading list implementation in my test application where I can clear the cache with a single button click. How can I get the cache size of the loaded images in the listview and clear the cache programmatically?
Here is the code for saving the cached images:
public ImageLoader(Context context){
//Make the background thead low priority. This way it will not affect the UI performance.
photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1);
mAssetManager = context.getAssets();
//Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
cacheDir = new File(android.os.Environment.getE开发者_如何学运维xternalStorageDirectory(),"LazyList");
else
cacheDir = context.getCacheDir();
if(!cacheDir.exists())
cacheDir.mkdirs();
}
EDIT:
So basically I added this piece of code in clearCache(), method, but I still cannot see the images start loading again when I'm scrolling.
public void clearCache() {
//clear memory cache
long size=0;
cache.clear();
//clear SD cache
File[] files = cacheDir.listFiles();
for (File f:files) {
size = size+f.length();
if(size >= 200)
f.delete();
}
}
To find the size of the cache directory use the codebelow.
public void clearCache() {
//clear memory cache
long size = 0;
cache.clear();
//clear SD cache
File[] files = cacheDir.listFiles();
for (File f:files) {
size = size+f.length();
f.delete();
}
}
This will return the number of bytes.
This has been more accurate to me:
private void initializeCache() {
long size = 0;
size += getDirSize(this.getCacheDir());
size += getDirSize(this.getExternalCacheDir());
}
public long getDirSize(File dir){
long size = 0;
for (File file : dir.listFiles()) {
if (file != null && file.isDirectory()) {
size += getDirSize(file);
} else if (file != null && file.isFile()) {
size += file.length();
}
}
return size;
}
In Kotlin, you can use:
context.cacheDir.walkBottomUp().fold(0L, { acc, file -> acc + file.length() })
or define it as an extension function
fun File.calculateSizeRecursively(): Long {
return walkBottomUp().fold(0L, { acc, file -> acc + file.length() })
}
// usage
val size = context.cacheDir.calculateSizeRecursively()
...and to clear cache, just delete the directory and recreate an empty one.
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