有时毕加索不会从内存缓存中加载图像

Question

 private class CustomAdapter extends CursorAdapter {

@Override
public void bindView(View view, Context context, Cursor cursor) {
    if (view != null) {

        String url = cursor.getString(CONTENT_URL_COLUMN);
        ViewHolder viewHolder = (ViewHolder) view.getTag();
        final ImageView imageView = viewHolder.mImageViewIcon;
        final TextView textView = viewHolder.mTextViewName;

            Picasso.with(context).load(url).into(new Target() {

                @Override
                public void onBitmapLoaded(Bitmap arg0, LoadedFrom arg1) {
                    imageView.setImageBitmap(arg0);
                    imageView.setVisibility(View.VISIBLE);
                    textView.setVisibility(View.GONE);
                }

                @Override
                public void onBitmapFailed(Drawable arg0) {
                    imageView.setVisibility(View.GONE);
                    textView.setVisibility(View.VISIBLE);
                }
             });
        }
    }
}
}

如果图像列表已经下载，那么在快速滚动列表时， onBitmapLoaded() 方法调用并从内存缓存中加载图像。但有时会调用 onBitmapFailed()。为什么？

Answer 1

您的Target 正在被垃圾收集，因为没有任何东西持有对它的引用。毕加索在持有ImageViews 或Targets 时使用WeakReference。

但是，您根本不需要使用Target。只需使用.into的回调，直接传递ImageView即可。

Picasso.with(context).load(url).into(imageView, new Callback() {
  @Override public void onSuccess() {
    imageView.setVisibility(VISIBLE);
    textView.setVisibility(GONE);
  }

  @Override public void onError() {
    imageView.setVisibility(GONE);
    textView.setVisibility(VISIBLE);
  }
});