Android getActivity()为空的问题解决办法

 protected void onCreate(Bundle savedInstanceState) {         .......         if (savedInstanceState != null) {             Parcelable p = savedInstanceState.getParcelable(FRAGMENTS_TAG);             mFragments.restoreAllState(p, nc != null ? nc.fragments : null);         }         mFragments.dispatchCreate();     }     protected void onSaveInstanceState(Bundle outState) {        super.onSaveInstanceState(outState);        Parcelable p = mFragments.saveAllState();       if (p != null) {          outState.putParcelable(FRAGMENTS_TAG, p);        }     }