android args.getString在null之外給出null onStart

Question

我在兩個片段之間傳遞一個字符串。它的工作，但對於原因，我不能讓在onStart外串...

public class EventSelectFriendFragment extends Fragment { 
final static String DATA_RECEIVE = "data_receive"; 
String passedPushId; 
Button create; 

@Override 
public void onStart() { 
    super.onStart(); 
    Bundle args = getArguments(); 
    if (args != null) { 
     passedPushId = args.getString(DATA_RECEIVE); 
     Log.d("passed id",args.getString(DATA_RECEIVE)); 
    } 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    // Inflate the layout for this fragment 
    View rootView = inflater.inflate(R.layout.fragment_event_select_friend, container, false); 




    create= (Button) rootView.findViewById(R.id.btnCreate); 

    btnMaakEvent.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      for(int i = selectedFriends.size()-1 ; i >= 0; i--){ 

       Log.d("array: ", i + selectedFriends.get(i).getFirstName()); 
       Log.d("passedPushId: ", passedPushId); 

      }    
     } 
    }); 

    return rootView; 
} 

}

處理通信passedPushId讓我從另一個片段中的字符串。 但是，當我想要在for循環中使用它時，passedPushId爲空...

Answer 1

onCreateView()早於onStart()被調用。一般來說，您應該初始化onCreate()內部參數Bundle的實例變量，而不是onStart()，因爲這在片段生命週期中要早得多。