何时调用 onRestoreInstanceState ？ （android kitkat）[重复]

Question

为了查看是否调用了onRestoreInstanceState，我做了这个小java代码

package com.MCHAppy.demostate.app;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;


public class MainActivity extends ActionBarActivity {
    private int visiters=0;

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

     }

     @Override
     protected void onResume() {
         super.onResume();
          visiters++;
         Log.d("Test","Resumed");
     }

     @Override
       protected void onSaveInstanceState(Bundle outState) {
           super.onSaveInstanceState(outState);
           outState.putInt("visiters",visiters);
           Log.d("Test",visiters+" visiters  was saved ");
       }

     @Override
     protected void onRestoreInstanceState(Bundle savedInstanceState) {
           super.onRestoreInstanceState(savedInstanceState);
           visiters=savedInstanceState.getInt("visiters");
           Log.d("Test",visiters+" visiters was restored");
     }
 }

当我点击主页图标时，我在 Logcat 中得到了这个

  06-09 17:09:58.240    1316-1316/com.MCHAppy.demostate.app D/MCHAppy﹕ 1 visiters  was saved

当我回到我的活动时，我在 Logcat 中得到了这个

06-09 17:58:13.230    1316-1316/com.MCHAppy.demostate.app D/MCHAppy﹕ Resumed

似乎从未调用过 onRestoreInstanceState 。真的是这样吗？

谢谢

Answer 1

通过the documentation

当活动从先前保存的状态重新初始化时，在 onStart() 之后调用此方法，此处在 savedInstanceState 中给出。

其中的关键部分是它仅在活动被重新初始化时调用。但是，始终会在 onCreate(Bundle savedInstanceState) 中传递相同的包，因此您可以将逻辑移到那里。

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if (savedInstanceState != null) {
        visiters=savedInstanceState.getInt("visiters");
    }
}