我在主活动中有包含recyclerview的片段
片段.java

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle   savedInstanceState) {
    super.onCreate(savedInstanceState);
    View view  = inflater.inflate(R.layout.activity_main, container, false);
    initInstances(view);
    setRetainInstance(true);
    return view;
}

private void initInstances(View view) {
    mRecyclerView = (RecyclerView) view.findViewById(R.id.dialogList);
    mLayoutManager = new LinearLayoutManager(getActivity());
    mRecyclerView.setLayoutManager(mLayoutManager);
    adapter = new MyAdapter(items);
    mRecyclerView.setAdapter(mAdapter);
}

main活动.java
在oncreate方法中:
myFragment = (MyFragment) getSupportFragmentManager().findFragmentByTag(MyFragment.TAG);
if (MyFragment == null) {
    MyFragment = new MyFragment();
    getSupportFragmentManager().beginTransaction().add(R.id.content_frame,
            myFragment, MyFragment.TAG).commit();
}

但当方向改变时,我的回收站视图重新绘制。
我已经尝试过这样覆盖onSaveInstanceStateonRestoreInstanceState的save stateHow to prevent custom views from losing state across screen orientation changesSaving and restoring view state android,但对我没有帮助
方向改变时,如何正确保存recyclerview和adapter项的状态?
解决方案:
我的片段通过一些方法从BaseFragment扩展而来:
public class BaseFragment extends Fragment{
Bundle savedState;

public BaseFragment() {
    super();
    if (getArguments() == null)
        setArguments(new Bundle());
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    if (!restoreStateFromArguments()) {
        onFirstTimeLaunched();
    }
}

protected void onFirstTimeLaunched() {

}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    saveStateToArguments();
}



public void saveStateToArguments() {
    if (getView() != null)
        savedState = saveState();
    if (savedState != null) {
        Bundle b = getArguments();
        b.putBundle("internalSavedViewState8954201239547", savedState);
    }
}



private boolean restoreStateFromArguments() {
    Bundle b = getArguments();
    savedState = b.getBundle("internalSavedViewState8954201239547");
    if (savedState != null) {
        onRestoreState(savedState);
        return true;
    }
    return false;
}

private Bundle saveState() {
    Bundle state = new Bundle();
    onSaveState(state);
    return state;
}

protected void onRestoreState(Bundle savedInstanceState) {

}

protected void onSaveState(Bundle outState) {

}

@Override
public void onStart() {
    super.onStart();
}

@Override
public void onStop() {
    super.onStop();
}


@Override
public void onDestroyView() {
    super.onDestroyView();
    saveStateToArguments();
}

在我的片段中,我重写方法并保存mlayoutmanager的状态
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setRetainInstance(true);
}

    @Override
protected void onSaveState(Bundle outState) {
    super.onSaveState(outState);
    outState.putParcelable("myState", mLayoutManager.onSaveInstanceState());
}

@Override
protected void onRestoreState(Bundle savedInstanceState) {
    super.onRestoreState(savedInstanceState);
    mLayoutManager.onRestoreInstanceState(savedInstanceState.getParcelable("myState"));
}

最佳答案

我搜索了如何获取RealReVIEW的滚动位置,但没有看到在哪里可以检索它,因此我认为最好的解决方案是直接处理Java代码中的旋转更改,并防止您的活动在方向更改上重新启动。
要防止在方向更改时重新启动,您可以遵循this solution
阻止活动重新启动后,您可以构建两个XML布局文件,一个用于纵向模式,另一个用于横向模式,然后在两个XML文件中添加一个FrameLayout,保留RecyclerView的位置。
调用onconfigurationchange(configuration newconfig)方法时,可以调用setcontentview(int layoutfile),并在新方向后使用适当的layoutfile,然后在framelayout中的类成员中添加您持有的recyclerview。

07-24 09:49
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