LRUCache写法

import android.support.v4.util.LruCache;


public class ImageCache {

private ImageCache() {
// use 1/8 of available heap size
cache = new LruCache((int) (Runtime.getRuntime().maxMemory() / 8)) {
              @Override
              protected int sizeOf(String key, Bitmap value) {
                  return value.getRowBytes() * value.getHeight();
              }
          };
}


private static ImageCache imageCache = null;


public static synchronized ImageCache getInstance() {
if (imageCache == null) {
imageCache = new ImageCache();
}
return imageCache;


}
private LruCache cache = null;

/**
* put bitmap to image cache
* @param key
* @param value
* @return  the puts bitmap
*/
public Bitmap put(String key, Bitmap value){
return cache.put(key, value);
}

/**
* return the bitmap
* @param key
* @return
*/
public Bitmap get(String key){
return cache.get(key);
}
}