应用程序关闭onbackpressed时出现Illegalstateexception

Question

我有一个带有2个标签的应用程序，其中添加了fragments。所以这就是层次结构：

MainActivity扩展了Activity：

TabHosts用于添加2个标签..每个标签都展开FragmentActivity

fragmentManager用于在每个标签中添加一个片段..每个片段都展开Fragment

我有overriden所有onstop方法，并在调用它们时记录。以防我在调用它时需要allowstatelosscommit。

问题：

如果我没有在选项卡之间切换回第四个，应用程序就可以正常关闭。但是当我做一些导航时，我最终得到了这个例外：

05-29 15:50:02.255: E/AndroidRuntime(12342): FATAL EXCEPTION: main
05-29 15:50:02.255: E/AndroidRuntime(12342): java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1343)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:486)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.support.v4.app.FragmentActivity.onBackPressed(FragmentActivity.java:179)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at orient.video.tabs.TabTVShows.onBackPressed(TabTVShows.java:222)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.app.Activity.onKeyUp(Activity.java:2099)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.KeyEvent.dispatch(KeyEvent.java:3200)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.app.Activity.dispatchKeyEvent(Activity.java:2329)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1806)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1246)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1246)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1246)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.widget.TabHost.dispatchKeyEvent(TabHost.java:298)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1246)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1246)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1246)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1246)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:1879)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1361)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.app.Activity.dispatchKeyEvent(Activity.java:2324)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1806)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewRootImpl.deliverKeyEventPostIme(ViewRootImpl.java:3327)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewRootImpl.handleFinishedEvent(ViewRootImpl.java:3300)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2460)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.os.Looper.loop(Looper.java:137)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at android.app.ActivityThread.main(ActivityThread.java:4424)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at java.lang.reflect.Method.invokeNative(Native Method)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at java.lang.reflect.Method.invoke(Method.java:511)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:848)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:575)
05-29 15:50:02.255: E/AndroidRuntime(12342):    at dalvik.system.NativeStart.main(Native Method)

由于状态正在搞乱，我希望在应用程序关闭时从fragmentmanager明确删除片段。我将onbackpressed挂钩在其中一个标签中：

    @Override
    public void onBackPressed() {
        // TODO Auto-generated method stub
        Log.v("tab tv", "back pressed");
        FragmentManager fm = getSupportFragmentManager();
        Log.v("frag backstack", String.valueOf(fm.getBackStackEntryCount()));
        super.onBackPressed();
    }

但backstackentrycount在我的情况下为0 ..当我发生这种情况时，没有tasks正在运行..我在这里做错了什么？？

修改

以下是我在OnCreate中添加标签的方法：

tabHost = (TabHost) findViewById(android.R.id.tabhost);
        LocalActivityManager mLocalActivityManager = new LocalActivityManager(this, false);
        mLocalActivityManager.dispatchCreate(savedInstanceState);
        tabHost.setup(mLocalActivityManager);
        TabSpec tab1 = tabHost.newTabSpec("TV Shows");
        TabSpec tab2 = tabHost.newTabSpec("Movies");
        tab1.setIndicator("TV Shows");
        tab1.setContent(new Intent(this, TabTVShows.class));
        tab2.setIndicator("Movies");
        tab2.setContent(new Intent(this, TabMovies.class));
        tabHost.addTab(tab1);
        tabHost.addTab(tab2);

以下是用于在标签中设置片段的PageAdapter：

public class VideosPageAdapter extends FragmentPagerAdapter implements IconPagerAdapter {
    private List<Fragment> fragments;

    public VideosPageAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        this.fragments = fragments;
    }

    @Override
    public Fragment getItem(int position) {

        return this.fragments.get(position);
    }

    @Override
    public int getCount() {
        return this.fragments.size();
    }

    @Override
    public int getIconResId(int index) {
        // TODO Auto-generated method stub
        return 0;
    }
}

这是我的标签代码：

 public class TabMovies extends FragmentActivity implements OnPageChangeListener {

        public static void notifyAdapter(List<Movie> movies)
            {
                numOfPages = (int)Math.ceil(movies.size()/(float)MainActivity.totalItems);
                List<Fragment> fragments = getFragments(numOfPages);        
                pageAdapter = new VideosPageAdapter(fm, fragments);        
                mViewPager.setAdapter(pageAdapter);
                pageAdapter.notifyDataSetChanged();
            }

private static List<Fragment> getFragments(int numOfPages) {
        List<Fragment> fList = new ArrayList<Fragment>();
        FragmentMoviesMain[] f = new FragmentMoviesMain[numOfPages];

        for (int i = 0; i < numOfPages; i++) {
            f[i] = new FragmentMoviesMain().newInstance(String
                    .valueOf(fragmentCounter));
            fragmentCounter++;
            fList.add(f[i]);
        }

        return fList;
    }