올해는 머신러닝이다.

java.lang.IllegalStateException: Activity has been destroyed
    at android.support.v4.app.FragmentManagerImpl.enqueueAction(Unknown Source)
    at android.support.v4.app.BackStackRecord.commitInternal(Unknown Source)
    at android.support.v4.app.BackStackRecord.commitAllowingStateLoss(Unknown Source)
    at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(Unknown Source)
    at android.support.v4.view.ViewPager.dataSetChanged(Unknown Source)
    at android.support.v4.view.ViewPager$PagerObserver.onChanged(Unknown Source)
    at android.database.DataSetObservable.notifyChanged(DataSetObservable.java:35)
    at android.support.v4.view.PagerAdapter.notifyDataSetChanged(Unknown Source)
    at com.douban.frodo.activity.AlbumPhotoActivity$AlbumPhotoPagerAdapter.b(Unknown Source)
    at com.douban.frodo.activity.AlbumPhotoActivity$10.a(Unknown Source)
    at com.douban.frodo.activity.AlbumPhotoActivity$10.onResponse(Unknown Source)
    at im.amomo.volley.OkRequest.deliverResponse(Unknown Source)
    at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(Unknown Source)
    at android.os.Handler.handleCallback(Handler.java:605)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:148)
    at android.app.ActivityThread.main(ActivityThread.java:4529)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:832)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
    at dalvik.system.NativeStart.main(Native Method)

mChildFragmentManager = null;

    /**
     * Adds an action to the queue of pending actions.
     *
     * @param action the action to add
     * @param allowStateLoss whether to allow loss of state information
     * @throws IllegalStateException if the activity has been destroyed
     */
    public void enqueueAction(Runnable action, boolean allowStateLoss) {
        if (!allowStateLoss) {
            checkStateLoss();
        }
        synchronized (this) {
            if (mDestroyed || mActivity == null) {
                throw new IllegalStateException("Activity has been destroyed");
            }
            if (mPendingActions == null) {
                mPendingActions = new ArrayList<Runnable>();
            }
            mPendingActions.add(action);
            if (mPendingActions.size() == 1) {
                mActivity.mHandler.removeCallbacks(mExecCommit);
                mActivity.mHandler.post(mExecCommit);
            }
        }
    }

@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);
    }
}