片段：onCreate被调用了4次

Question

I have a Working model of fragments, when i was debugging the code i saw that the Fragment onCreate is being called 4 times.

Below is my code: MyFragmentActivity

class MyFragmentActivity extends FragmentActivity{

@Override
    public void onCreate(Bundle savedInstanceState) {
      if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction().replace(fragmentID, new MyListFragmentt())
            .replace(detailFragmentID, new MyDetailFragment()).commit();
        }
}

@Override
    protected void onRestart() {
        getSupportFragmentManager().beginTransaction().replace(detailFragmentID, new MyDetailFragment()).commitAllowingStateLoss();
}

}

MyDetailFragment.class

class MyDetailFragment extends Fragment{

// has method like oncreate(),onCreateView(),onSaveInstanceState()
}

How my oncreate of MyDetailFragment is called ? When i go to some other activity and come back and then tilt the device only then oncreate and onSaveInstanceState of MyDetailFragment is called multiple times.

How can i solve this, i have looked into few posts on SO but it says that we need use HIDE,Show methods and other things ? but What is the proper soultion to this ?

EDIT

When i am coming back from previous activity, my data in the MyDetailFragment needs to be refreshed.

Answer 1

    i think ur recreating fragments multiple times, u do new MyListFragment everytime on onCreate function, call findFragmentByTag to get the existing fragment and set that, if null (first time) then create one

/ here is some code mate, if this doesnt work and ur app has single fragment better to just create xml and have only a fragment tag in it, and set that xml in setContentView function * /

    // declare following member variable
    MyFragment _fragment;

    // in onCreate function, call this method

    private void setupFragment()
    {
         _fragment = (MyFragment)getFragmentManager().findFragmentByTag("MyFragment");
         if(null == _fragment)
         {
    _fragment = new MyFragment();
    }
    // now do the fragment transaction
FragmentTransaction trans = getFragmentManager().beginTransaction();
trans.add(containerId, _fragment, "MyFragment"); // here tag is important
trans.commit();
    }

Answer 2

Try this

MyDetailFragment fragment = new MyDetailFragment();
@Override
    public void onCreate(Bundle savedInstanceState) {
      if (savedInstanceState == null) {

        getSupportFragmentManager().beginTransaction().replace(fragmentID, new MyListFragmentt())
            .replace(detailFragmentID, fragment).commit();
        }
}

@Override
    protected void onRestart() {
        if(fragment != null) {
        getSupportFragmentManager().beginTransaction().replace(detailFragmentID, fragment).commitAllowingStateLoss();
        }
}