相关疑难解决方法(0)

我对Android的RecyclerView.State有疑问.

我正在使用RecyclerView,我如何使用它并将其与RecyclerView.State绑定？

我的目的是保存RecyclerView的滚动位置.

我正在将ListViews迁移到RecyclerViews.使用listviews,我使用此处描述的常用技术来存储和恢复活动之间的滚动位置.

如何使用RecyclerViews做同样的事情？在RecyclerView.onSaveInstanceState()似乎有protected访问权限,因此无法直接使用.

如何获得滚动Recyclerview或Layoutmanager？

我可以通过添加一个来测量滚动位置OnScrollListener,但是当Orientation更改scrollDy为0时.

    mRecyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
            int scrollDy = 0;
            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
            }

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                scrollDy += dy;
            }
        });

我正在用 gridlayoutManager 填充 recyclerView。现在我想在屏幕旋转上保存滚动位置。

我尝试使用 onSaveInstanceState 和 onRestoreInstanceState() 这样做，如本文所示：

如何使用 RecyclerView.State 保存 RecyclerView 的滚动位置？

下面是我的代码：

@Override
protected void onSaveInstanceState(Bundle outState) {
    Log.e(TAG, "onSaveInstanceState");
    super.onSaveInstanceState(outState);
    outState.putParcelable(KEY_INSTANCE_STATE_RV_POSITION, 
    gridLayoutManager.onSaveInstanceState());
 }


@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {

    Log.e(TAG, "onRestoreInstanceState");
    super.onRestoreInstanceState(savedInstanceState);
    if (savedInstanceState!= null){
        Parcelable savedState = 
    savedInstanceState.getParcelable(KEY_INSTANCE_STATE_RV_POSITION);

        movieAdapter.addAll(movieItemList);
        if (savedState!= null){
            gridLayoutManager.onRestoreInstanceState(savedState);
        }
    }
}


//this is my movieAdapter.addAll() method 

public void addAll(List<MovieItem>items){

    movieItems = items;
}


//This is the method to get lists of movies from ViewModel Class

private void loadFavMovies() {
    FavViewModel …