ActivityManagerがアプリケーションを終了させると、ViewPagerアプリケーションを7個のタブ、フラグメント内のすべてのWebViewを復元できません。

Question

7個のタブを持つViewPagerアプリケーションがあります。すべてのタブはWebViewsです。私はアプリから離れて切り替えるまで、アプリは素晴らしい作品です。

私がActivityManagerが私を追い出す前にアプリに戻っても、それはまだまだ素晴らしいことです。問題は私が記憶から追い出されたときに起こります。それは戻って、正しいタブに復元し、クラッシュします。私はinitWebViewへの呼び出しを削除しようとしました（下記参照）。このメソッドは、Javaスクリプトを有効にするなどの設定を復元します。復元時にこのinitを実行しないと、クラッシュすることはありませんが、ページが空白になります（mWebView.getSettings（）。setJavaScriptEnabled（true）を呼び出さなかったためです）。

ここにあります

package com.mobilityinitiative.synergyworldwide; 

import java.util.ArrayList; 

import android.app.AlertDialog; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.net.ConnectivityManager; 
import android.net.NetworkInfo; 
import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentActivity; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.app.FragmentTransaction; 
import android.support.v4.view.PagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.util.Log; 

import com.actionbarsherlock.app.ActionBar; 
import com.actionbarsherlock.app.ActionBar.Tab; 
import com.actionbarsherlock.app.SherlockFragmentActivity; 

public class SynergyWorldwideActivity extends SherlockFragmentActivity 
{ 
final static private String tag = SynergyWorldwideActivity.class.getSimpleName(); 
ViewPager mViewPager; 
TabsAdapter mTabsAdapter; 
final static private int mMaxTabs = 1; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    Log.i(tag,"onCreate"); 

    // Set up the view pager 
    setContentView(R.layout.fragment_tabs_pager); 
    mViewPager = (ViewPager)findViewById(R.id.pager); 
    mViewPager.setOffscreenPageLimit(mMaxTabs); 

    // Set up action bar 
    final ActionBar bar = getSupportActionBar(); 
    bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 
    bar.setDisplayShowTitleEnabled(true); 

    // Test for internet connectivity 
    if(!isOnline()) 
    { 
     AlertDialog.Builder builder = new AlertDialog.Builder(this); 
     builder.setMessage(R.string.internet_not_on) 
       .setCancelable(false) 
       .setPositiveButton("OK", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int id) { 
         SynergyWorldwideActivity.this.finish(); 
        } 
       }); 
     AlertDialog alert = builder.create(); 
     alert.show(); 
    } 


    // Creat tabs with bundled URLs 
    Bundle tab1Args=new Bundle(), tab2Args=new Bundle(), tab3Args=new Bundle(), 
      tab4Args=new Bundle(), tab5Args=new Bundle(), tab6Args=new Bundle(), tab7Args=new Bundle(); 
    tab1Args.putString("tabURL", getString(R.string.webtab1_URL)); 
    tab2Args.putString("tabURL", getString(R.string.webtab2_URL)); 
    tab3Args.putString("tabURL", getString(R.string.webtab3_URL)); 
    tab4Args.putString("tabURL", getString(R.string.webtab4_URL)); 
    tab5Args.putString("tabURL", getString(R.string.webtab5_URL)); 
    tab6Args.putString("tabURL", getString(R.string.webtab6_URL)); 
    tab7Args.putString("tabURL", getString(R.string.webtab7_URL)); 

    mTabsAdapter = new TabsAdapter(this, mViewPager); 
    mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.webtab1_name)), 
      MyWebviewFragment.class, tab1Args); 
    mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.webtab2_name)), 
      MyWebviewFragment.class, tab2Args); 
    mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.webtab3_name)), 
      MyWebviewFragment.class, tab3Args); 
    mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.webtab4_name)), 
      MyWebviewFragment.class, tab4Args); 
    mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.webtab5_name)), 
      MyWebviewFragment.class, tab5Args); 
    mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.webtab6_name)), 
      MyWebviewFragment.class, tab6Args); 
    mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.webtab7_name)), 
      MyWebviewFragment.class, tab7Args); 

    if (savedInstanceState != null) { 
     Log.i(tag,"onCreate: savedInstanceState: tab = " + savedInstanceState.getInt("tab", 0)); 
     bar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0)); 
    } 
    Log.i(tag,"***** Exiting onCreate *****"); 

} 

public boolean isOnline() { 
    Log.i(tag,"isOnline"); 

    ConnectivityManager cm = 
     (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); 
    NetworkInfo netInfo = cm.getActiveNetworkInfo(); 
    if (netInfo != null && netInfo.isConnectedOrConnecting()) { 
     Log.i(tag,"isOnline: returning true"); 
     return true; 
    } 
    Log.i(tag,"isOnline: returning false"); 
    return false; 
} 

@Override 
protected void onSaveInstanceState(Bundle outState) { 
    super.onSaveInstanceState(outState); 
    Log.i(tag,"onSaveInstanceState: tab = " + getActionBar().getSelectedNavigationIndex()); 
    outState.putInt("tab", getActionBar().getSelectedNavigationIndex()); 
    Log.i(tag,"***** Exiting onSaveInstanceState *****"); 
} 

/** 
* TabsAdapater class 
*/ 
public static class TabsAdapter extends FragmentPagerAdapter implements ActionBar.TabListener, ViewPager.OnPageChangeListener{ 
    final static private String tag = TabsAdapter.class.getSimpleName(); 
    private final Context mContext; 
    private final ActionBar mActionBar; 
    private final ViewPager mViewPager; 
    private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>(); 

    static final class TabInfo { 
     private final Class<?> clss; 
     private final Bundle args; 

     TabInfo(Class<?> _class, Bundle _args) { 
      clss = _class; 
      args = _args; 
     } 
    } 

    public TabsAdapter(FragmentActivity activity, ViewPager pager) { 
     super(activity.getSupportFragmentManager()); 
     Log.i(tag,"TabsAdapter: constructor"); 

     mContext = activity; 
     mActionBar = ((SherlockFragmentActivity) activity).getSupportActionBar(); 
     mViewPager = pager; 
     mViewPager.setAdapter(this); 
     mViewPager.setOnPageChangeListener(this); 
     Log.i(tag,"***** Exiting TabsAdapter: constructor *****"); 
    } 

    public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) { 
     Log.i(tag,"addTab"); 

     TabInfo info = new TabInfo(clss, args); 
     tab.setTag(info); 
     tab.setTabListener(this); 
     mTabs.add(info); 
     mActionBar.addTab(tab); 
     notifyDataSetChanged(); 
     Log.i(tag,"***** Exiting addTab *****"); 
    } 


    @Override 
    public int getItemPosition(Object object) 
    { 
     Log.i(tag,"getItemPosition"); 
     return PagerAdapter.POSITION_UNCHANGED; 
    } 

    @Override 
    public int getCount() 
    { 
     //Log.i(tag,"getCount"); 
     int iCount = mTabs.size(); 
     //Log.i(tag,"***** Exiting getCount *****"); 
     return iCount; 
    } 

    @Override 
    public Fragment getItem(int position) 
    { 
     Log.i(tag,"getItem: " + position); 
     TabInfo info = mTabs.get(position); 
     Fragment frag = Fragment.instantiate(mContext, info.clss.getName(), info.args); 
     Log.i(tag,"***** Exiting getItem: " + position + " *****"); 
     return frag; 
    } 

    @Override 
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) 
    { 
     //Log.i(tag,"onPageScrolled: " + position); 
    } 

    @Override 
    public void onPageSelected(int position) 
    { 
     Log.i(tag,"onPageSelected: " + position); 
     mActionBar.setSelectedNavigationItem(position); 
     Log.i(tag,"***** Exiting onPageSelected *****"); 
    } 

    @Override 
    public void onPageScrollStateChanged(int state) 
    { 
     //Log.i(tag,"onPageScrollStateChanged"); 
    } 

    @Override 
    public void onTabSelected(Tab tab, FragmentTransaction ft) 
    { 
     Log.i(tag,"onTabSelected: " + tab.getPosition()); 
     Object tabTag = tab.getTag(); 
     int numTabs = mTabs.size(); 
     for (int i=0; i<numTabs; i++) { 
      if (mTabs.get(i) == tabTag) { 
       mViewPager.setCurrentItem(i); 
      } 
     } 
     Log.i(tag,"***** onTabSelected: " + tab.getPosition() + " *****"); 
    } 

    @Override 
    public void onTabUnselected(Tab tab, FragmentTransaction ft) 
    { 
     Log.i(tag,"onTabUnselected: " +tab.getPosition()); 
    } 

    @Override 
    public void onTabReselected(Tab tab, FragmentTransaction ft) 
    { 
     Log.i(tag,"onTabRelected: " +tab.getPosition()); 
    } 
    } 
} 

とフラグメントのコード：二つのファイルのためのコードである。

package com.mobilityinitiative.synergyworldwide; 

import android.app.ProgressDialog; 
import android.content.Context; 
import android.content.Intent; 
import android.content.res.Configuration; 
import android.graphics.Bitmap; 
import android.net.ConnectivityManager; 
import android.net.NetworkInfo; 
import android.net.Uri; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.KeyEvent; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.view.View.OnKeyListener; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 

import com.actionbarsherlock.app.SherlockFragment; 
import com.actionbarsherlock.view.Menu; 
import com.actionbarsherlock.view.MenuInflater; 
import com.actionbarsherlock.view.MenuItem; 

public class MyWebviewFragment extends SherlockFragment 
{ 
final static private String tag = MyWebviewFragment.class.getSimpleName(); 
String mTabURL; 
private WebView mWebView = null; 
static final int REFRESH_ID = Menu.FIRST; 
private ProgressDialog spinnerDlg; 

/** 
* When creating, retrieve this instance's number from its arguments. 
*/ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    Log.i(tag,"onCreate"); 

    super.onCreate(savedInstanceState); 

    // Tell the framework to try to keep this fragment around 
    // during a configuration change. 
    setRetainInstance(true); 

    mTabURL = getArguments() != null ? getArguments().getString("tabURL") : "http://www.google.com"; 
    Log.i(tag,"***** Exiting onCreate: URL = " + mTabURL + " *****"); 
} 

/** 
* The Fragment's UI is just a simple text view showing its 
* instance number. 
*/ 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
{ 
    Log.i(tag,"onCreateView"); 

    // Create view object to return 
    View v = inflater.inflate(R.layout.webview_layout, container, false); 

    // Check to see if it has been saved and restore it if true 
    if(savedInstanceState != null) 
    { 
     Log.i(tag,"savedInstance != null in onCreateView - attempting to restore view"); 

     if (savedInstanceState.isEmpty()) 
      Log.i(tag, "Can't restore state because bundle is empty."); 
     else 
     { 

      mWebView = ((WebView)v.findViewById(R.id.webview_fragment)); 
      if(mWebView.restoreState(savedInstanceState) == null) 
      { 
       Log.i(tag, "Restoring state FAILED!"); 
      } 
      else 
      { 
       Log.i(tag, "*!*!*!*!*!*! Restoring state succeeded. *!*!*!*!*!*!"); 
       initWebView(); 
      } 
     } 

    } 
    else 
    { 
     Log.i(tag,"savedInstance == null in onCreateView - creating new webview"); 
     // Load web page 
     mWebView = (WebView)v.findViewById(R.id.webview_fragment); 
     Log.i(tag, ">>>>>> Calling initWebView on NEW tab <<<<<"); 
     initWebView(); 
     mWebView.loadUrl(mTabURL); 

    } 
    Log.i(tag, "***** Exiting onCreateView *****"); 
    return v; 
} 

void initWebView() 
{ 
    Log.i(tag, "initWebView"); 

    mWebView.getSettings().setJavaScriptEnabled(true); 
    mWebView.setOnKeyListener(new OnKeyListener(){ 
     @Override 
     public boolean onKey(View v, int keyCode, KeyEvent event) 
     { 
      if ((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()) { 
       mWebView.goBack(); 
       return true; 
      } 
      return false; 
     } 

    }); 

    // Used to be in new creation 
    mWebView.setWebViewClient(new MyWebViewClient()); 
    mWebView.getSettings().setPluginsEnabled(true); 
    mWebView.getSettings().setBuiltInZoomControls(false); 
    mWebView.getSettings().setSupportZoom(false); 
    mWebView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true); 
    mWebView.getSettings().setAllowFileAccess(true); 
    mWebView.getSettings().setDomStorageEnabled(true); 

    Log.i(tag, "***** Exit initWebView *****"); 
} 

@Override 
public void onSaveInstanceState(Bundle outState) 
{ 
    Log.i(tag,"onSaveInstanceState"); 

    if(mWebView != null) 
    { 
     if(mWebView.saveState(outState) == null) 
      Log.i(tag,"Saving state FAILED!"); 
     else 
      Log.i(tag, "Saving state succeeded."); 
    } 
    else 
     Log.i(tag, "No webview to save in onSaveInstanceState"); 
    Log.i(tag,"***** Exiting onSaveInstanceState *****"); 
} 

@Override 
public void onActivityCreated(Bundle savedInstanceState) 
{ 
    Log.i(tag,"onActivityCreated"); 
    super.onActivityCreated(savedInstanceState); 
    setHasOptionsMenu(true); 
    Log.i(tag,"***** Exiting onActivityCreated *****"); 
} 

@Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 
    Log.i(tag,"onCreateOptionsMenu"); 

    Log.i(tag,"onCreateOptionsMenu - menu loaded: " + mTabURL); 
    menu.add(Menu.NONE, REFRESH_ID, 0, getString(R.string.refresh_string)) 
      .setIcon(R.drawable.ic_action_refresh) 
      .setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS); 
    Log.i(tag,"***** Exiting onCreateOptionsMenu *****"); 
} 

@Override public boolean onOptionsItemSelected(MenuItem item) { 
    Log.i(tag,"onOptionsItemSelected"); 

    boolean refreshItem = false; 

    switch (item.getItemId()) { 
     case REFRESH_ID: 
      if(mWebView != null) 
       mWebView.reload(); 
      refreshItem = true; 

     default: 
      refreshItem = super.onOptionsItemSelected(item); 
    } 
    return refreshItem; 
} 

@Override 
public void onDestroy() 
{ 
    Log.i(tag,"onDestroy"); 
    super.onDestroy(); 
    Log.i(tag,"***** Exiting onDestroy *****"); 
} 

@Override 
public void onDestroyView() 
{ 
    Log.i(tag,"onDestroyView"); 
    super.onDestroyView(); 
    Log.i(tag,"***** Exiting onDestroyView *****"); 
} 

@Override 
public void onPause() 
{ 
    Log.i(tag,"onPause"); 
    super.onPause(); 
    mWebView.onPause(); 
    Log.i(tag,"***** Exiting onPause *****"); 
} 

@Override 
public void onResume() 
{ 
    Log.i(tag,"onResume"); 
    super.onResume(); 
    mWebView.onResume(); 
    Log.i(tag,"***** Exiting onResume *****"); 
} 

public boolean isOnline() { 
    Log.i(tag,"isOnline"); 

    ConnectivityManager cm = 
     (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE); 
    NetworkInfo netInfo = cm.getActiveNetworkInfo(); 
    if (netInfo != null && netInfo.isConnectedOrConnecting()) { 
     Log.i(tag,"***** Exiting isOnline: returning true *****"); 
     return true; 
    } 
    Log.i(tag,"***** Exiting isOnline: returning false *****"); 
    return false; 
} 

@Override 
public void onConfigurationChanged(Configuration newConfig) 
{ 
    Log.i(tag,"onConfigurationChanged"); 
    super.onConfigurationChanged(newConfig); 
    Log.i(tag,"***** Exiting onConfigurationChanged *****"); 
} 


public class MyWebViewClient extends WebViewClient { 
    final private String tag = MyWebViewClient.class.getSimpleName(); 

    @Override 
    public boolean shouldOverrideUrlLoading(WebView view, String url) { 
    // YouTube video link 
     Log.i(tag, "shouldOverrideUrlLoading"); 
     if (url.startsWith("http://youtu.be")) 
     { 
      String urlSubString = url.substring("http://youtu.be/".length()); 
      String newURL = String.format("http://www.youtube.com/v/%s", urlSubString); 
      startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(newURL))); 
      return (true); 
     } 
     Log.i(tag, "***** Exiting shouldOverrideUrlLoading *****"); 
     return (false); 
    } 

    @Override 
    public void onPageStarted(WebView view, String url, Bitmap favicon) { 
     super.onPageStarted(view, url, favicon); 
     //Log.i(tag, "onPageStarted"); 
     if(spinnerDlg == null) 
     { 
      spinnerDlg = new ProgressDialog(getActivity()); 
      spinnerDlg.setMessage("Loading...."); 
      spinnerDlg.show(); 
     } 
     //Log.i(tag, "***** Exiting onPageStarted *****"); 
    } 

    @Override 
    public void onPageFinished(WebView view, String url) { 
     super.onPageFinished(view, url); 
     //Log.i(tag, "onPageFinished"); 
     if(spinnerDlg != null) 
     { 
      spinnerDlg.dismiss(); 
     } 
     spinnerDlg = null; 
     //Log.i(tag, "***** Exiting onPageFinished *****"); 
    } 

    /* (non-Javadoc) 
    * @see android.webkit.WebViewClient#onReceivedError(android.webkit.WebView, int, java.lang.String, java.lang.String) 
    */ 
    @Override 
    public void onReceivedError(WebView view, int errorCode, 
      String description, String failingUrl) 
    { 
     Log.i(tag,"onReceivedError - Error Code: " + errorCode + " Error Description: " + description + " Failing URL: " + failingUrl); 
     super.onReceivedError(view, errorCode, description, failingUrl); 

    } 
} 
} 

私が言ったように、私は完全な損失でだが、私は、私はどちらかだと確信しています情報を正しく保存したり、正しく復元したりすることはできませんが、わかりません。

これを調べてもらいたい方は、事前におねがいします。

Answer 1

onLowMemory()を実装してみませんか？私はあなたのアプリが閉鎖される前にこれが呼び出されると感じています。あなたはアプリの状態を保存して、それをきれいにすることができます。