SherlockListFragment setRetainInstance（true）无法按预期工作

Question

我在setRetainInstance(true)上使用SherlockListFragment，并期望它在屏幕旋转期间不会破坏并重新创建。但事实并非如此。每次我执行轮换时它仍然会调用onActivityCreated。

WatchlistFragment.java

package org.yccheok.jstock.gui;

import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;

import com.actionbarsherlock.app.SherlockFragment;
import com.actionbarsherlock.app.SherlockListFragment;

public class WatchlistFragment extends SherlockListFragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.i(TAG, "WatchlistFragment onCreate");
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        Log.i(TAG, "WatchlistFragment onActivityCreated");

        // Not sure why. After I setRetainInstance to true, onActivityCreated is still
        // called for each screen rotation changes.
        setRetainInstance(true);

        setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, getTimeConsumingData()));
    }

    public String[] getTimeConsumingData() {
        Log.i(TAG, "WatchlistFragment getTimeConsumingData");
        return new String[] { "A", "B", "C"};
    }

    private static final String TAG = WatchlistFragment.class.getSimpleName();
}

JStockFragmentActivity.java

package org.yccheok.jstock.gui;

import android.os.Bundle;
import android.util.Log;

import com.actionbarsherlock.app.SherlockFragmentActivity;

public class JStockFragmentActivity extends SherlockFragmentActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "JStockFragmentActivity onCreate");
        super.onCreate(savedInstanceState);     
        setContentView(R.layout.jstock_fragment_activity);
    }

    private static final String TAG = JStockFragmentActivity.class.getSimpleName();
}

jstock_fragment_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <fragment class="org.yccheok.jstock.gui.WatchlistFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

我为每次轮换获得了以下logcat

02-25 20:11:10.562: I/JStockFragmentActivity(6989): JStockFragmentActivity onCreate
02-25 20:11:10.597: I/WatchlistFragment(6989): WatchlistFragment onCreate
02-25 20:11:10.613: I/WatchlistFragment(6989): WatchlistFragment onActivityCreated
02-25 20:11:10.613: I/WatchlistFragment(6989): WatchlistFragment getTimeConsumingData
02-25 20:11:12.078: I/JStockFragmentActivity(6989): JStockFragmentActivity onCreate
02-25 20:11:12.109: I/WatchlistFragment(6989): WatchlistFragment onCreate
02-25 20:11:12.121: I/WatchlistFragment(6989): WatchlistFragment onActivityCreated
02-25 20:11:12.121: I/WatchlistFragment(6989): WatchlistFragment getTimeConsumingData
02-25 20:11:17.492: I/JStockFragmentActivity(6989): JStockFragmentActivity onCreate
02-25 20:11:17.519: I/WatchlistFragment(6989): WatchlistFragment onCreate
02-25 20:11:17.527: I/WatchlistFragment(6989): WatchlistFragment onActivityCreated
02-25 20:11:17.527: I/WatchlistFragment(6989): WatchlistFragment getTimeConsumingData

我认为让setRetainInstance(true)在轮换期间不能一次又一次地创建WatchlistFragment？

Answer 1

根据the specs：

这是正确的

  

  
• onDestroy()将不会被调用（但onDetach()仍然会被调用，因为片段正在与其当前活动分离。）
  
• onCreate(Bundle)将不会被调用，因为片段没有被重新创建。
  
• onAttach(Activity)和 onActivityCreated(Bundle)仍会被称为。
  

Answer 2

是的，它会调用onActivityCreated()，但不会调用onCreate()和onCreateView()。因此，请将您不希望再次调用的代码移至onCreate()。