問題描述

Activty嵌套多個Fragment，然后Fragment里面再嵌套多個Fragment，外層的Fragment切換得快了或者橫豎屏切換就會報錯：java.lang.IllegalStateException: Activity has been destroyedat android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1460)at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:634)at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:613)怎么解決？

報錯的是外層Fragment內的下面這段代碼：

IndexListFragment indexHotFragment = new IndexListFragment();Bundle bundle = new Bundle();switch (id) { case 1:bundle.putSerializable('list', audit_handles);bundle.putInt('id', 1);break; case 2:bundle.putSerializable('list', pos_handles);bundle.putInt('id', 2);break; case 3:bundle.putSerializable('list', audit_lists);bundle.putInt('id', 3);break; case 4:bundle.putSerializable('list', pos_lists);bundle.putInt('id', 4);break; default:break; } indexHotFragment.setArguments(bundle); FragmentManager fragmentManager = getChildFragmentManager(); FragmentTransaction ft = fragmentManager.beginTransaction(); ft.replace(flContainer, indexHotFragment); ft.commit();

然后我查了網上的資料，都說加下面一段：

@Overridepublic void onDetach() {super.onDetach(); try {Field childFragmentManager = Fragment.class.getDeclaredField('mChildFragmentManager ');childFragmentManager.setAccessible(true);childFragmentManager.set(this, null); } catch (NoSuchFieldException e) {throw new RuntimeException(e); } catch (IllegalAccessException e) {throw new RuntimeException(e); }}

這個方法怎么用，“mChildFragmentManager”需要替換成什么，，感覺不管用呢？

問題解答

其實有一個辦法是if(getActivity()==null){ return;}if(getActivity().isFishing()){return;}不知道你是否能理解我的意思。

你需要恢復FragmentManager中為你保存的fragment.在創建fragment之前,判斷一下savedInstanceState,像這樣:

@Override public void onViewStateRestored(@Nullable Bundle savedInstanceState) {super.onViewStateRestored(savedInstanceState);if (savedInstanceState != null) { FragmentManager fm = getChildFragmentManager(); // tag 是你在add fragment的時候穿進去的值. mFragment = (Fragment) fm.findFragmentByTag(tag);} }

另外,我好奇你fragment嵌套的時候,是怎么add進去的.不會也是用反射得到mChildFragmentManager然后再操作的吧? getChildFragmentManager()就可以得到childFragmentManager.

具體可以參見 https://segmentfault.com/q/10...