当活动进入后台时，调用onSaveInstanceState（隐藏）

Question

我有一个简单的场景，MainActivity的Launch按钮启动第二个Activity。在第二个Activity中，我根据用户点击动态添加视图，但是当我返回主Activity并返回第二个活动时，添加的视图不会保存。我发现只要按下主页按钮并调用onSaveInstanceState，当我进入活动时它就会被恢复，但是当我去MainActivity时，onSaveInstanceState没有被调用，视图就消失了。

所以我希望能够知道当活动进入后台隐藏状态时如何调用onSaveInstanceState（）。或者关于如何保存ViewGroup的任何其他想法

public class CountActivity extends AppCompatActivity{

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.counter_activity);
        container = (LinearLayout) findViewById(R.id.counterContainer);
        sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
        Log.d("TAG","CountActivity onCreate");
    }

    public void AddCounter(View view) {
        View parent = (View) view.getParent();
        LayoutInflater layoutInflater =
                (LayoutInflater) getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        final View addedView = layoutInflater.inflate(R.layout.fragment_counter, null);
        container.addView(addedView);
    }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {
        super.onSaveInstanceState(savedInstanceState);
        Log.d("TAG", "CountActivity onSaveInstanceState");

    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        Log.d("TAG", "CountActivity onRestoreInstanceState");
    }

    @Override
    protected void onPause() {
        Log.d("TAG", "CountActivity onPause");
        super.onPause();
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.d("TAG", "CountActivity onRestart");
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.d("TAG", "CountActivity onResume");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d("TAG", "CountActivity onDestroy");
    }

    @Override
    protected void onStop() {
        super.onStop();
        Log.d("TAG", "CountActivity onDestroy");
    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.d("TAG", "CountActivity onStart");
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        Log.d("TAG", "CountActivity onConfigurationChanged");
    }
}