'boolean androidx.fragment.app.FragmentManagerImpl.isDestroyed()' 在空对象引用上

Question

我收到此错误崩溃

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method boolean androidx.fragment.app.FragmentManagerImpl.isDestroyed()' on a null object reference

当活动 onStop() 以及当我从 FragmentTransaction 中删除片段时

我加了

@Override
public 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);
    }
}

对我所有的片段，但这无济于事

我的代码

FragmentTransaction t = getSupportFragmentManager().beginTransaction();
                    //t.replace(R.id.calendar1, weekendCaldroidFragment);
                    t.detach(weekendCaldroidFragment).add(R.id.calendar1, weekendCaldroidFragment).attach(weekendCaldroidFragment).commitNowAllowingStateLoss();

Answer 1

从 onDetach() 中删除所有这些代码 - 在任何最新版本的 Fragments 上都不需要这样做，而这正是导致崩溃的原因。