RecyclerView使用——精确恢复到上次浏览位置

在开发中,例如:文件管理器,点击进入其他文件夹中,返回上一级目录时所在位置和之前浏览一样.

1.在recyclerView的滑动监听中:

private RecyclerView mFolderRv; private int lastPosition = 0;//RecyclerView的第一个可视item的position private int lastOffset = 0;//与RecyclerView顶部的偏移量 .... mFolderRv.addOnScrollListener(new RecyclerView.OnScrollListener() { @Override public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) { super.onScrollStateChanged(recyclerView, newState); if (mFolderRv.getLayoutManager() != null) { LinearLayoutManager mLayoutManager = (LinearLayoutManager) mFolderRv.getLayoutManager(); View topView = mLayoutManager.getChildAt(0); //获取第一个可视的item if (topView != null) { lastOffset = topView.getTop(); lastPosition = mLayoutManager.getPosition(topView); } Log.i(TAG, "onScrollStateChanged: topView=" + topView + " lastOffset=" + lastOffset + " lastPosition=" + lastPosition); } } });

2.在需要恢复位置处: 例如 文件管理器就在返回上一级目录的事件中

((LinearLayoutManager) mFolderRv.getLayoutManager()).scrollToPositionWithOffset(lastPosition, lastOffset);