Android LruCache in ListView
package zhangphil.cache; import android.app.ListActivity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.os.Bundle; import android.util.Log; import android.util.LruCache; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.ImageView; public class MainActivity extends ListActivity { private LruCache<String, Bitmap> mLruCache; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); int CACHE_SIZE = 8 * 1024 * 1024; mLruCache = new LruCache(CACHE_SIZE); ArrayAdapter mAdapter = new ArrayAdapter(this, 0) { @NonNull @Override public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) { ImageView image = new ImageView(getContext()); load(R.mipmap.ic_launcher, image); return image; } @Override public int getCount() { return 20; } }; setListAdapter(mAdapter); } private void load(int id, ImageView image) { Bitmap bmp = mLruCache.get(String.valueOf(id)); if (bmp == null) { Log.d("LruCache缓存", "没有缓存,开始创建新数据资源并缓存之。"); bmp = BitmapFactory.decodeResource(getResources(), id); mLruCache.put(String.valueOf(id), bmp); } else { Log.d("LruCache缓存", "已有缓存,复用。"); image.setImageBitmap(bmp); } } }