previous片段的onSaveInstanceState的上称为定向电流片段 [英] onSaveInstanceState of previous fragment is called on-orientation of current fragment

问题描述

我在做什么：

• 我打开一个片段（例如::片段-A ）的容器，并在
  的onSaveInstanceState 事件我正在存储一些数据包

我用的是code 的

  @覆盖
    公共无效的onSaveInstanceState（捆绑outState）{
        super.onSaveInstanceState（outState）;        outState.putInt（yourSpinner，spnSearchByCity.getSelectedItemPosition（））;    }
 

• 现在，我替换的容器与片段-B 按钮的点击
  在片段-A

我用的是code 的

 片段= FrgMdMap.newInstance（messengerObj）;                    如果（片段！= NULL）{
                        。getFragmentManager（）调用BeginTransaction（）取代（R.id.content_frame，片段）.addToBackStack（空）.commit（）;
                    }
 

• 我能够成功加载片段-B




• 现在的片段-B的方向改变的的onSaveInstanceState 的
  片段-A ID射击

---

问题：

• 这是怎么了结的地方？


• 如何确保这不会发生？

解决方案

 这是怎么了结的地方？
 

实际上片段-A 仍然活着，以及下方的片段-B 这是因为 addToBackStack（空）补充，当你更换的片段。

 如何确保这不会发生？
 

您可以删除 addToBackStack（空）或计数在的onSaveInstanceState 法层叠片段的数量和时它是0，那么你可以运行里面的code你的的onSaveInstanceState

编辑：

 公共无效的onSaveInstanceState（捆绑outState）{
    super.onSaveInstanceState（outState）;
    FragmentManager FM = getActivity（）getSupportFragmentManager（）。
    如果（fm.getBackStackEntryCount（）== 0）
    outState.putInt（yourSpinner，spnSearchByCity.getSelectedItemPosition（））;}
 

What i am doing ::

• I load a fragment(eg:: Fragment-A) to the container, and in onSaveInstanceState event i am storing some data into bundle

i use the code

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

        outState.putInt("yourSpinner", spnSearchByCity.getSelectedItemPosition());

    }

• Now i replace the container with Fragment-B on click of button in Fragment-A

i use the code

fragment = FrgMdMap.newInstance(messengerObj);

                    if (fragment != null) {
                        getFragmentManager().beginTransaction().replace(R.id.content_frame, fragment).addToBackStack(null).commit();
                    }

• I am successfully able to load the Fragment-B

• Now on orientation change of Fragment-B the onSaveInstanceState of Fragment-A id firing

---

Questions::

• How is this taking place ?
• How can i make sure this wont happen ?

解决方案

How is this taking place ?

Actually Fragment-A is still alive and well underneath your Fragment-B that is due to the addToBackStack(null) added when you replaced the fragment.

How can i make sure this wont happen ?

You can remove the addToBackStack(null) or count the number of stacked fragments in your onSaveInstanceState method and when it is 0 then you can run the code inside your onSaveInstanceState

EDIT:

public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    FragmentManager fm = getActivity().getSupportFragmentManager();
    if(fm.getBackStackEntryCount() == 0)
    outState.putInt("yourSpinner", spnSearchByCity.getSelectedItemPosition());

}

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