A reference to the destroyed activity, although the WeakReference method was used

In Action onCreate

Check some deleted data first if it hasn't been verified yet, then refresh the interface:

private static WeakReference<MainActivity> wrActivity = null;

protected void onCreate(final Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  wrActivity = new WeakReference<MainActivity>(this);
  // ...
}

private class InitTask extends AsyncTask<Object, Void, Bundle> {
  @Override
  protected Bundle doInBackground(Object... params) {
    // checking some (network) stuff

    return (Bundle) params[0];
  }

  @Override
  protected void onPostExecute(final Bundle savedInstanceState) {
    if (wrActivity.get() == null || wrActivity.get().isFinishing()) {
      return;
    }

    updateUi(savedInstanceState);
  }
}

private void updateUi(Bundle savedInstanceState) {
  Log.d(getClass().getSimpleName(), "updateUi()");

  if (savedInstanceState == null) {
    resetActionBar();
  }

  initPagerAndTabs(savedInstanceState);

  // ...
}

private void initPagerAndTabs(Bundle savedInstanceState) {
  Log.d(getClass().getSimpleName(), "initPagerAndTabs()");
  mTabNames = getResources().getStringArray(R.array.tabs);

  mAdapter = new FragmentAdapter(getSupportFragmentManager());
  mPager = (ViewPager) findViewById(R.id.pager);
  mPager.setAdapter(mAdapter);
  mPager.setOnPageChangeListener(mAdapter);
  // ...
}

      

        
        
        
      

    

But sometimes my application crashes with this:

java.lang.IllegalStateException: Activity has been destroyed
  at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1376)
  at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
  at android.support.v4.app.BackStackRecord.commitAllowingStateLoss(BackStackRecord.java:578)
  at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:139)
  at android.support.v4.view.ViewPager.setAdapter(ViewPager.java:415)
  at com.mypackage.MainActivity.access$9(MainActivity.java:1358)
  at com.mypackage.MainActivity$InitTask.onPostExecute(MainActivity.java:1)

      

        
        
        
      

    

Line 1358 matches exactly one:

private void updateUi(Bundle savedInstanceState) {

      

        
        
        
      

    

So, WeakReference

(pattern) doesn't get rid of me by AsyncTask

returning the result to another MainActivity.

What's the best approach in this case? ServiceIntent

?