每次方向更改片段崩溃都会出错：
01-26 12:46:43.215 2895-2895/com.cbsystematic.mobile.itvdn
E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.cbsystematic.mobile.itvdn, PID: 2895
java.lang.RuntimeException: Unable to destroy activity {com.cbsystematic.mobile.itvdn/com.cbsystematic.mobile.itvdn.NavigationActivity}: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3671)
at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3689)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3889)
at android.app.ActivityThread.access$900(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1284)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1365)
at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:516)
at com.cbsystematic.mobile.itvdn.LessonsFragment.replaceFragment(LessonsFragment.java:126)
at com.cbsystematic.mobile.itvdn.LessonsFragment.onDetach(LessonsFragment.java:119)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1080)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1108)
at android.support.v4.app.FragmentManagerImpl.dispatchDestroy(FragmentManager.java:1954)
at android.support.v4.app.FragmentActivity.onDestroy(FragmentActivity.java:313)
at android.support.v7.app.ActionBarActivity.onDestroy(ActionBarActivity.java:169)
at android.app.Activity.performDestroy(Activity.java:6112)
at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1140)
at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3658)
at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3689)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3889)
at android.app.ActivityThread.access$900(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1284)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
我需要保存当前片段的状态。
片段类代码：
public class LessonsFragment extends Fragment implements AbsListView.OnItemClickListener {
private OnFragmentInteractionListener mListener;
/**
* The fragment's ListView.
*/
private AbsListView mListView;
/**
* The Adapter which will be used to populate the ListView/GridView with
* Views.
*/
private ListAdapter mAdapter;
private static String courseUrl;
private ParserJson parserJson = new ParserJson();
private TextView descriptionTextView;
private DescriptionData descriptionData;
// TODO: Rename and change types of parameters
public static LessonsFragment newInstance(String url) {
LessonsFragment fragment = new LessonsFragment();
courseUrl = url;
return fragment;
}
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public LessonsFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// TODO: Change Adapter to display your content
mAdapter = new LessonsItemAdapter(getActivity(),
R.layout.lessons_list_item, parserJson.getLessons(courseUrl).getLessonsArray());
descriptionData = parserJson.getLessons(courseUrl).getDescriptionData();
}
// @Override
// public void onSaveInstanceState(Bundle outState) {
// //No call for super(). Bug on API Level > 11.
// }
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_lessons_list, container, false);
descriptionTextView = (TextView) view.findViewById(R.id.lessons_description);
descriptionTextView.setText("Описание курса:\n" +
descriptionData.getShortDescription());
// Set the adapter
mListView = (AbsListView) view.findViewById(android.R.id.list);
((AdapterView<ListAdapter>) mListView).setAdapter(mAdapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
return view;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
//this occurs when we move out of this Fragment
replaceFragment(CatalogFragment.newInstance(1));
}
private void replaceFragment (Fragment fragment){
String backStateName = fragment.getClass().getName();
String fragmentTag = backStateName;
boolean fragmentPopped = getFragmentManager().popBackStackImmediate (backStateName, 0);
if (!fragmentPopped && getFragmentManager().findFragmentByTag(fragmentTag) == null){ //fragment not in back stack, create it.
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.container, fragment, fragmentTag);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.addToBackStack(backStateName);
ft.commit();
}
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (null != mListener) {
mListener.onLessonFragmentInteraction(parserJson.getLessons(courseUrl).getLessonsArray().get(position).getId());
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onLessonFragmentInteraction(String id);
}
}
清单：
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".AuthorizationActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".NavigationActivity"
android:parentActivityName="com.cbsystematic.mobile.itvdn.AuthorizationActivity" >
<!-- The meta-data element is needed for versions lower than 4.1 -->
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.cbsystematic.mobile.itvdn.AuthorizationActivity" />
>
</activity>
</application>
片段的布局：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/fragment_lessons"
android:background="#FAF9F9"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.cbsystematic.mobile.itvdn.LessonsFragment">
<TextView
android:id="@+id/lessons_description"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#acacac" />
<ListView android:id="@android:id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/lessons_description"/>
我知道这些问题就像颈部疼痛一样。但请给出你的假设。
将不胜感激任何帮助。
答案 0 :(得分：5)
崩溃是因为每次更改方向时都会重新创建片段。
将此行添加到清单中的活动：
android:configChanges="keyboardHidden|orientation|screenSize"