Question

在我的RecyclerView Adapter我使用以下方法记住当前所选项目并在屏幕旋转时恢复它：

private final static String SELECTED_ITEM = "MyAdapter.selectedItem";

public void onSaveInstanceState(Bundle outState){
    Log.i("onSave","OnSave "+mSelectedItem);
    outState.putInt(SELECTED_ITEM, mSelectedItem);
}

public void onRestoreInstanceState(Bundle savedInstanceState){
    if(savedInstanceState.containsKey(SELECTED_ITEM)){
        Log.i("onRestore","OnRestore " + savedInstanceState.getInt(SELECTED_ITEM));
        notifyItemChanged(mSelectedItem);
        mSelectedItem = savedInstanceState.getInt(SELECTED_ITEM);
        notifyItemChanged(mSelectedItem);
        mRecyclerView.getLayoutManager().scrollToPosition(mSelectedItem);
    }
}

在我的Fragment中包含我正在使用的RecyclerView：

@Override
public void onSaveInstanceState(Bundle outState) {
    if(null != mRecyclerView && null != mRecyclerView.getAdapter()){
        ((MyAdapter)mRecyclerView.getAdapter()).onSaveInstanceState(outState);
    }
    super.onSaveInstanceState(outState);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    if(null!=savedInstanceState){
        if(null != mRecyclerView && null != mRecyclerView.getAdapter()){
            ((MyAdapter)mRecyclerView.getAdapter()).onRestoreInstanceState(savedInstanceState);
        }
    }
}

我看到Log条消息，但Adapter不记得选择。

Answer 1

感谢Selvin的code，我很快意识到问题是我在每次屏幕旋转时重新创建Fragment而新的Fragment当然没有选择int还原

在您的根onCreate的{{1}}方法中，检查您是否是第一次创建Activity：

Activity

然后在@Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.main_layout); mContentLayout = (FrameLayout)findViewById(R.id.main_content_frame); if(null==savedInstanceState) { mFragment = new MyFragment(); FragmentManager fragmentManager = getSupportFragmentManager(); FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); fragmentTransaction.replace(mContentLayout.getId(), mPlatformsFragment); fragmentTransaction.commit(); } }中，要保存所选项目，请使用：

Fragment

RecyclerView不记得屏幕旋转时的选择

1 个答案: