我采用了@(Kirk Woll)建议的解决方案，它对我很有效。我还在“联系人”应用程序的Android源代码中看到，他们使用了类似的技术。我还想补充一些具体情况: 在我的listactivity派生类的顶部:

private static final String LIST_STATE = "listState";
private Parcelable mListState = null;

然后，一些方法重写:

@Override
protected void onRestoreInstanceState(Bundle state) {
    super.onRestoreInstanceState(state);
    mListState = state.getParcelable(LIST_STATE);
}

@Override
protected void onResume() {
    super.onResume();
    loadData();
    if (mListState != null)
        getListView().onRestoreInstanceState(mListState);
    mListState = null;
}

@Override
protected void onSaveInstanceState(Bundle state) {
    super.onSaveInstanceState(state);
    mListState = getListView().onSaveInstanceState();
    state.putParcelable(LIST_STATE, mListState);
}

当然，“loadData”是我从DB中检索数据并将其放入列表的函数。

在我的Froyo设备上，当你改变手机方向时，当你编辑一个项目并返回列表时，这都是有效的。

最好的解决方案是:

// save index and top position
int index = mList.getFirstVisiblePosition();
View v = mList.getChildAt(0);
int top = (v == null) ? 0 : (v.getTop() - mList.getPaddingTop());

// ...

// restore index and position
mList.post(new Runnable() {
    @Override
    public void run() {
      mList.setSelectionFromTop(index, top);
   }
});

你必须在邮件和线程中调用!

警告! !在AbsListView中有一个错误，如果ListView.getFirstVisiblePosition()为0，则不允许onSaveState()正确工作。

所以，如果你有大图像，占据了屏幕的大部分，你滚动到第二张图像，但第一张图像的一部分正在显示，滚动位置将不会被保存…

从AbsListView.java:1650(评论我)

// this will be false when the firstPosition IS 0
if (haveChildren && mFirstPosition > 0) {
    ...
} else {
    ss.viewTop = 0;
    ss.firstId = INVALID_POSITION;
    ss.position = 0;
}

但在这种情况下，下面代码中的“top”将是一个负数，这将导致其他问题，阻止状态被正确恢复。所以当'top'为负时，就得到下一个子结点

// save index and top position
int index = getFirstVisiblePosition();
View v = getChildAt(0);
int top = (v == null) ? 0 : v.getTop();

if (top < 0 && getChildAt(1) != null) {
    index++;
    v = getChildAt(1);
    top = v.getTop();
}
// parcel the index and top

// when restoring, unparcel index and top
listView.setSelectionFromTop(index, top);

private Parcelable state;
@Override
public void onPause() {
    state = mAlbumListView.onSaveInstanceState();
    super.onPause();
}

@Override
public void onResume() {
    super.onResume();

    if (getAdapter() != null) {
        mAlbumListView.setAdapter(getAdapter());
        if (state != null){
            mAlbumListView.requestFocus();
            mAlbumListView.onRestoreInstanceState(state);
        }
    }
}

这就够了

我的答案是Firebase和位置0是一个变通办法

Parcelable state;

DatabaseReference everybody = db.getReference("Everybody Room List");
    everybody.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            state = listView.onSaveInstanceState(); // Save
            progressBar.setVisibility(View.GONE);
            arrayList.clear();
            for (DataSnapshot messageSnapshot : dataSnapshot.getChildren()) {
                Messages messagesSpacecraft = messageSnapshot.getValue(Messages.class);
                arrayList.add(messagesSpacecraft);
            }
            listView.setAdapter(convertView);
            listView.onRestoreInstanceState(state); // Restore
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {
        }
    });

和convertView

位置0 a添加一个您不使用的空白项

public class Chat_ConvertView_List_Room extends BaseAdapter {

private ArrayList<Messages> spacecrafts;
private Context context;

@SuppressLint("CommitPrefEdits")
Chat_ConvertView_List_Room(Context context, ArrayList<Messages> spacecrafts) {
    this.context = context;
    this.spacecrafts = spacecrafts;
}

@Override
public int getCount() {
    return spacecrafts.size();
}

@Override
public Object getItem(int position) {
    return spacecrafts.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@SuppressLint({"SetTextI18n", "SimpleDateFormat"})
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        convertView = LayoutInflater.from(context).inflate(R.layout.message_model_list_room, parent, false);
    }

    final Messages s = (Messages) this.getItem(position);

    if (position == 0) {
        convertView.getLayoutParams().height = 1; // 0 does not work
    } else {
        convertView.getLayoutParams().height = RelativeLayout.LayoutParams.WRAP_CONTENT;
    }

    return convertView;
}
}

我已经看到这个工作暂时不打扰用户，我希望它为您工作

我使用的是FirebaseListAdapter，不能让任何解决方案工作。我最后做了这个。我猜有更优雅的方式，但这是一个完整的和有效的解决方案。

在onCreate之前:

private int reset;
private int top;
private int index;

FirebaseListAdapter内部:

@Override
public void onDataChanged() {
     super.onDataChanged();

     // Only do this on first change, when starting
     // activity or coming back to it.
     if(reset == 0) {
          mListView.setSelectionFromTop(index, top);
          reset++;
     }

 }

启动时间：

@Override
protected void onStart() {
    super.onStart();
    if(adapter != null) {
        adapter.startListening();
        index = 0;
        top = 0;
        // Get position from SharedPrefs
        SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
        top = sharedPref.getInt("TOP_POSITION", 0);
        index = sharedPref.getInt("INDEX_POSITION", 0);
        // Set reset to 0 to allow change to last position
        reset = 0;
    }
}

停止：

@Override
protected void onStop() {
    super.onStop();
    if(adapter != null) {
        adapter.stopListening();
        // Set position
        index = mListView.getFirstVisiblePosition();
        View v = mListView.getChildAt(0);
        top = (v == null) ? 0 : (v.getTop() - mListView.getPaddingTop());
        // Save position to SharedPrefs
        SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
        sharedPref.edit().putInt("TOP_POSITION" + "", top).apply();
        sharedPref.edit().putInt("INDEX_POSITION" + "", index).apply();
    }
}

因为我还必须解决这个FirebaseRecyclerAdapter，我在这里发布的解决方案:

在onCreate之前:

private int reset;
private int top;
private int index;

FirebaseRecyclerAdapter内部:

@Override
public void onDataChanged() {
    // Only do this on first change, when starting
    // activity or coming back to it.
    if(reset == 0) {
        linearLayoutManager.scrollToPositionWithOffset(index, top);
        reset++;
    }
}

启动时间：

@Override
protected void onStart() {
    super.onStart();
    if(adapter != null) {
        adapter.startListening();
        index = 0;
        top = 0;
        // Get position from SharedPrefs
        SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
        top = sharedPref.getInt("TOP_POSITION", 0);
        index = sharedPref.getInt("INDEX_POSITION", 0);
        // Set reset to 0 to allow change to last position
        reset = 0;
    }
}

停止：

@Override
protected void onStop() {
    super.onStop();
    if(adapter != null) {
        adapter.stopListening();
        // Set position
        index = linearLayoutManager.findFirstVisibleItemPosition();
        View v = linearLayoutManager.getChildAt(0);
        top = (v == null) ? 0 : (v.getTop() - linearLayoutManager.getPaddingTop());
        // Save position to SharedPrefs
        SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
        sharedPref.edit().putInt("TOP_POSITION" + "", top).apply();
        sharedPref.edit().putInt("INDEX_POSITION" + "", index).apply();
    }
}