使用 LRU 快取的點陣圖快取
LRU 快取
以下示例程式碼演示了用於快取影象的 LruCache 類的可能實現。
private LruCache<String, Bitmap> mMemoryCache;
這裡字串值是點陣圖值的關鍵。
// Get max available VM memory, exceeding this amount will throw an
// OutOfMemory exception. Stored in kilobytes as LruCache takes an
// int in its constructor.
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
// Use 1/8th of the available memory for this memory cache.
final int cacheSize = maxMemory / 8;
mMemoryCache = new LruCache<String, Bitmap>(cacheSize) {
@Override
protected int sizeOf(String key, Bitmap bitmap) {
// The cache size will be measured in kilobytes rather than
// number of items.
return bitmap.getByteCount() / 1024;
}
};
用於將點陣圖新增到記憶體快取
public void addBitmapToMemoryCache(String key, Bitmap bitmap) {
if (getBitmapFromMemCache(key) == null) {
mMemoryCache.put(key, bitmap);
}
}
從記憶體快取中獲取點陣圖
public Bitmap getBitmapFromMemCache(String key) {
return mMemoryCache.get(key);
}
要將點陣圖載入到 imageview,只需使用 getBitmapFromMemCache(Pass key
)。