Android的碎片状态总是空的onCreateView方法和onActivityCreated方法 [英] Android fragment state always null in onCreateView method and onActivityCreated method

问题描述

我用的片段类多个选项卡。我是在拯救片段的状态失败。我用的方法的onSaveInstanceState（）并保存参数在里面。但是，当我回到这个片段保存的状态总是显示空。我尝试了所有的问题，并就以this.Still我面临同样的问题的答案。请任何人都可以帮我解决这个问题。

我的code

  @覆盖
 公共无效的onCreate（捆绑savedInstanceState）{
   // TODO自动生成方法存根
   super.onCreate（savedInstanceState）;
   setRetainInstance（真）;
   super.onCreate（savedInstanceState）;
   Log.d（savedInstanceStateInfo1，+ savedInstanceState）;
   如果（NULL！= savedInstanceState）{
    nAndroids = savedInstanceState.getInt（nAndroids）;
    Log.d（NANDROIDS，+ nAndroids）;
   }
  }
  // Log.d（国家在OnCreate中：，+ savedInstanceState）; @覆盖
 公共无效onActivityCreated（捆绑savedInstanceState）{
  super.onActivityCreated（savedInstanceState）;
  setRetainInstance（真）;
  Log.d（SavedinstanestateInfo，+ savedInstanceState）;
 } @覆盖
 公共查看onCreateView（LayoutInflater充气器，容器的ViewGroup，
  捆绑savedInstanceState）{
  // TODO自动生成方法存根
  如果（集装箱== NULL）{
   返回null;
  }
  //最后的动作条AB = getActivity（）getSupportActionBar（）。  视图V =（的LinearLayout）inflater.inflate（R.layout.infotab，集装箱，FALSE）;
  Log.d（SavedinstanestateInfo，+ savedInstanceState）;
  返回伏;
 }
 @覆盖
 公共无效的onSaveInstanceState（捆绑outState）{
  outState.putInt（nAndroids，nAndroids）;  super.onSaveInstanceState（outState）;
 }
 

解决方案

1）显然使用setRetainInstance（真）时，该套件，onRestoreInstanceState为null。

http://stackoverflow.com/a/8488107/1011746

2）没有必要的，但更习惯进行任何修改outState之前调用super.onSaveInstanceState（outState）。同为super.onRestoreInstanceState（outState）在onRestoreInstanceState（捆绑outState）。

I have used multiple tabs in fragment class. I was failed in saving the state of fragment. I used the method onSaveInstanceState() and save a parameter in it. But when I came back to this fragment the saved state always shows "null". I tried all the questions and answers regarding to this.Still I am facing the same problem. Please could anyone help me to solve this.

MY CODE

 @Override
 public void onCreate(Bundle savedInstanceState) {
   // TODO Auto-generated method stub
   super.onCreate(savedInstanceState);
   setRetainInstance(true);
   super.onCreate(savedInstanceState);
   Log.d("savedInstanceStateInfo1", "" + savedInstanceState);
   if (null != savedInstanceState) {
    nAndroids = savedInstanceState.getInt("nAndroids");
    Log.d("NANDROIDS", "" + nAndroids);
   }
  }
  // Log.d("State in oncreate : ",""+savedInstanceState);

 @Override
 public void onActivityCreated(Bundle savedInstanceState) {
  super.onActivityCreated(savedInstanceState);
  setRetainInstance(true);
  Log.d("SavedinstanestateInfo", "" + savedInstanceState);
 }

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
  Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  if (container == null) {
   return null;
  }
  // final ActionBar ab=getActivity().getSupportActionBar();

  View v = (LinearLayout) inflater.inflate(R.layout.infotab, container, false);
  Log.d("SavedinstanestateInfo", "" + savedInstanceState);
  return v;
 }
 @Override
 public void onSaveInstanceState(Bundle outState) {
  outState.putInt("nAndroids", nAndroids);

  super.onSaveInstanceState(outState);
 }

解决方案

1) Apparently when using setRetainInstance(true), the Bundle for onRestoreInstanceState is null.

http://stackoverflow.com/a/8488107/1011746

2) Not necessary, but more customary to call super.onSaveInstanceState(outState) before making any modifications to outState. Same for super.onRestoreInstanceState(outState) in onRestoreInstanceState(Bundle outState).

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