爲什麼數據保存在onSaveInstanceState（）方法返回null

Question

我保存這個字符串與onSaveInstanceState（）方法的onSaveInstanceState（）方法的關鍵「消息」只是在onCreate（）方法顯示一個toast它不工作。我究竟做錯了什麼 ？

@Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     initComponents(); 
     onClickLogin(); 

     if(savedInstanceState!=null){ 
      String message = savedInstanceState.getString("message"); 
      Toast.makeText(this, message, Toast.LENGTH_LONG).show(); 
     } 
    } 

    @Override 
    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) { 
     super.onSaveInstanceState(outState, outPersistentState); 
     outState.putString("message", "This is my message to be reloaded"); 
    } 

我已經嘗試在下面的onSaveInstanceState（）中切換2語句，但我得到了相同的結果。

@Override 
    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) { 
     outState.putString("message", "This is my message to be reloaded"); 
     super.onSaveInstanceState(outState, outPersistentState); 
    } 

Answer 1

必須覆蓋有沒有PersistableBundle outPersistentState另一種方法。

@Override 
    public void onSaveInstanceState(Bundle outState) { 
     super.onSaveInstanceState(outState); 
     outState.putString("message", "This is my message to be reloaded"); 
    }