java - ActionBarActivity 返回 api10f 的 ListFragment 时出现问题

Question

我有一个 android.support.v7.app.ActionBarActivity，它有一个 FrameLayout，其中包含 SupportMapFragment 和 android.support .v4.app.ListFragment.

我在 ActionBarActivity 的 OnCreate 中实例化这两个 fragment

        if(mFM.findFragmentByTag("ListFragment")==null){
            mPlaceListFragment = new PlaceListFragment_1();
            mFM.beginTransaction().add(R.id.listfragment_container, mPlaceListFragment,"ListFragment").commit();
        }else{
            mPlaceListFragment = (PlaceListFragment_1)mFM.findFragmentByTag("ListFragment");
        }

        if(mFM.findFragmentByTag("MapFragment")==null){
            mMapFragment = new map_fragment(); //always create map fragment
            mFM.beginTransaction().add(R.id.mapfragment_container, mMapFragment,"MapFragment").commit();
        }else{
            mMapFragment = (map_fragment) mFM.findFragmentByTag("MapFragment");
        }

为了避免在选择每个 fragment 时重新创建每个 fragment ，我根据选择的 fragment 隐藏/显示它们。

@Override
public boolean onNavigationItemSelected(int i, long l) { //OnFragmentInteractionListener

    FragmentTransaction ft = mFM.beginTransaction();

    if(i==0){
        //map
        if (mPlaceListFragment.isVisible())ft.hide(mPlaceListFragment);
        if (mMapFragment.isHidden())ft.show(mMapFragment);
    }else{
        //list
        if (mPlaceListFragment.isHidden())ft.show(mPlaceListFragment);
        if (mMapFragment.isVisible())ft.hide(mMapFragment);
    }

    ft.commit();

    return true; //True if the event was handled, false otherwise.
}

这一切都运行良好。我可以使用 ActionBar 中的下拉菜单选择每个 fragment 并操作 UI 等。方向更改也可以正常工作。 当 ListFragment 可见并且应用程序打开一个新的 Activity 并按下后退键返回到原始 Activity 时，就会出现此问题。

或者

ListFragment 可见，按下 HOME 按钮并尝试从任务栏重新打开应用程序。

map fragment 不会出现问题，只有 ListFragment 才会出现此问题。该应用程序还适用于 API17+ 的 GenyMotion 模拟器

应用程序返回到 ListFragment 正常，但 UI 控件(操作栏控件和 Activity 下拉列表等)没有响应，并且屏幕淡出并变得无响应。

没有 LogCat 错误。

这似乎是 API10 的问题，并且在返回 ListFragment 时发生？

覆盖 ActionBarActivity

@Override
protected void onResume() {
    //activity - after onstart
    super.onResume();
    if(mAdView!=null) mAdView.resume();

    FragmentTransaction ft = mFM.beginTransaction();

    if(getSupportActionBar().getSelectedNavigationIndex()==0){
        //show map
        ft.show(mMapFragment);
        ft.hide(mPlaceListFragment);
    }else{
        //show ListFragment
        ft.show(mPlaceListFragment);
        ft.hide(mMapFragment);
    }
    ft.commit();
}

@Override
protected void onPause() {
    //activity
    if(mAdView!=null)  mAdView.pause();
    super.onPause();
}

@Override
protected void onStop() {
    super.onStop();
    // If the client is connected
    if (mLocationClient!=null && mLocationClient.isConnected()) {
        /*
         * Remove location updates for a listener.
         * The current Activity is the listener, so
         * the argument is "this".
         */
        mLocationClient.removeLocationUpdates(this);
        mLocationClient.disconnect();
    }


    EasyTracker.getInstance(this).activityStop(this);//put as last statement
}

@Override
protected void onDestroy() {
    //activity
    if(mAdView!=null) mAdView.destroy();
    super.onDestroy();
    //clean the file cache when root activity exit
    //the resulting total cache size will be less than 3M
    if(isTaskRoot()){
        AQUtility.cleanCacheAsync(this);
    }

    if (mLocationClient !=null && !mLocationClient.isConnected()) mLocationClient.disconnect();

}



        ********************************************************************
        //All handlers are set in Oncreate of main ActionBarActivity e.g.
        //ActionBar Spinner
       ********************************************************************

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
            mSpinnerAdapter = ArrayAdapter.createFromResource(actionBar.getThemedContext(), R.array.action_list, android.R.layout.simple_spinner_dropdown_item);
        }else{
            mSpinnerAdapter = ArrayAdapter.createFromResource(actionBar.getThemedContext(), R.array.action_list, android.R.layout.simple_spinner_dropdown_item);
            //mSpinnerAdapter = ArrayAdapter.createFromResource(actionBar.getThemedContext(), R.array.action_list, R.layout.navigation_spinner_item);
        }
        actionBar.setListNavigationCallbacks(mSpinnerAdapter, this);

         ********************************************************************
        //other spinners and views belonging to main activity
         ********************************************************************
        mSprSavedPlaces = (Spinner) findViewById(R.id.spr_saved_places);
        mSprSavedPlaces.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
               //stuff
             }

         //Also the Map and List fragments are repopuplated from via the main
         //ActionBarActivity’s onSaveInstanceState and onRestoreInstanceState
         //this seems to work ok. 

<小时/>

不久前发布的这个问题引发了与我遇到的相同问题:Back button very slow

Answer 1

终于我找到了解决这个问题的方法。总之，在 SupportMapFragment 和 ListFragment 之间切换时出现问题。 FragmentTransaction 类的隐藏/显示方法用于在单个 FrameLayout 中存储的两个 fragment 之间进行切换。但是，如果 SupportMapFragment 处于隐藏状态，并且控制权被传递给新 Activity 并再次返回，则返回时会出现很大的延迟，并且 UI 将无响应。

如果 SupportMapFragment 可见，则没有问题。仅 Android 2.3.3 (Samsung Galaxy) 手机出现此问题，运行 HoneyComb + 的模拟器没有问题

请参阅下面的解决方案描述和代码:

/**
 * Show selected fragment and hide other.
 *
 * Could not use ft.hide/show for SupportMapFragment because this caused
 * big delays coming back to main screen from other activities when the SupportMapFragment was
 * in its hidden state. It also caused the UI to become unresponsive.
 * 
 * I solved this by hiding/showing the SupportMapFragment by removing/adding the fragment for
 * its container view. Working on 2.3.3 and Honeycomb --> KitKat emulators
 */
private void showFragment(Fragment fragmentIn) {
    if (fragmentIn == null || mFragmentVisible == fragmentIn) {
        return;
    }

    View mapView=mMapFragment.getView();

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

    if(fragmentIn instanceof map_fragment){
        //show map
        if (mapView.getParent()!=mFragmentContainer) { //mFragmentContainer is FrameLayout
            mFragmentContainer.addView(mapView);
        }
        ft.hide(mPlaceListFragment);
    }else{
        //show list
        mFragmentContainer.removeView(mapView);
        ft.show(mPlaceListFragment);
    }

    ft.commit();

    mFragmentVisible = fragmentIn;
}