IllegalStateException in a ListFragment

Question

我有一个类应该填充一个listview。我在另一个活动中使用了相同的代码(而不是片段)，它运行得很好。在这个片段中，它给了我一个"IllegalStateException“.

这是日志：

04-02 14:08:21.505: E/AndroidRuntime(25925): FATAL EXCEPTION: main
04-02 14:08:21.505: E/AndroidRuntime(25925): Process: com.social.bearv2, PID: 25925
04-02 14:08:21.505: E/AndroidRuntime(25925): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.social.bearv2/com.social.bearv2.PagerTabsActivity}: java.lang.IllegalStateException: Content view not yet created
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2215)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2265)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.ActivityThread.access$800(ActivityThread.java:145)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1206)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.os.Handler.dispatchMessage(Handler.java:102)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.os.Looper.loop(Looper.java:136)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.ActivityThread.main(ActivityThread.java:5081)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at java.lang.reflect.Method.invokeNative(Native Method)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at java.lang.reflect.Method.invoke(Method.java:515)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:607)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:126)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at dalvik.system.NativeStart.main(Native Method)
04-02 14:08:21.505: E/AndroidRuntime(25925): Caused by: java.lang.IllegalStateException: Content view not yet created
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.support.v4.app.ListFragment.ensureList(ListFragment.java:328)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.support.v4.app.ListFragment.getListView(ListFragment.java:222)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at com.social.bearv2.Page2Fragment.<init>(Page2Fragment.java:46)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at java.lang.Class.newInstanceImpl(Native Method)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at java.lang.Class.newInstance(Class.java:1208)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.support.v4.app.Fragment.instantiate(Fragment.java:402)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.support.v4.app.Fragment.instantiate(Fragment.java:377)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at com.social.bearv2.PagerTabsActivity.onCreate(PagerTabsActivity.java:36)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.Activity.performCreate(Activity.java:5231)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-02 14:08:21.505: E/AndroidRuntime(25925):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2169)
04-02 14:08:21.505: E/AndroidRuntime(25925):    ... 12 more

这是一堂课：

public class Page2Fragment extends ListFragment {
     List<NameValuePair> nameValuePairs;
     ArrayList<String> items = null;
     HttpClient httpclient;
     HttpPost httppost;
     HttpResponse response;
     HttpEntity httpentity;
     String is;
     private static SharedPreferences pref;
     private TextView testo;


    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {


        // Se container è vuoto restituisco null
        if (container == null) {
            return null;
        }
        // Altrimenti faccio l'inflate della view dal layout
        View view = (LinearLayout) inflater.inflate(R.layout.page2, container,
                false);

        Context ctx = getActivity();
          Resources res = ctx.getResources();
          String[] achievements = getResources().getStringArray(R.array.achievements);
          TypedArray immagini = res.obtainTypedArray(R.array.immagini);

          setListAdapter(new TestImmagineAdapter(ctx, R.layout.riga_lista, achievements, immagini));

          //setListAdapter(new ArrayAdapter<String>(this, R.layout.riga_lista, achievements));

          final ListView lv = getListView();
          lv.setTextFilterEnabled(true);
          testo = (TextView) view.findViewById(R.id.testo_vista);
          pref = getActivity().getSharedPreferences("MainActivity", 0);
          final SharedPreferences.Editor editor = pref.edit();
          if(pref.getInt("ach1", 0)== 1) {
              lv.getChildAt(0).setBackgroundColor(Color.WHITE);
          }
          lv.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
              // When clicked, show a toast with the TextView text
              //Toast.makeText(getApplicationContext(), testo.getText(),
                  //Toast.LENGTH_SHORT).show();
                int num = position;
                  Log.i("Elemento numero:", Integer.toString(num));   
            }
          });
        return view;
    }

}

Answer 1

1. onCreateView不应该返回null。
2. 您应该使用onCreateView来返回充气的View，并使用onViewCreated查找充气视图的元素。onViewCreated的第一个参数是您膨胀的View。 公共视图onCreateView(LayoutInflater inflater，ViewGroup容器，Bundle savedInstanceState) {返回inflater.inflate(R.layout.page2，容器，false)；} @Override void onViewCreated(View view，Bundle savedInstanceState) { Context ctx =getActivity(GetActivity)；Resources res = ctx.getResources()；String[]绩效= res.obtainTypedArray(R.array.immagini)；setListAdapter(ctx，R.array.immagini，成就，immagini))；final lv.getChildAt(0).setBackgroundColor(Color.WHITE)；lv = getListView()；lv.setTextFilterEnabled(真)；testo = (TextView) view.findViewById(R.id.testo_vista)；pref =getListView 0；最终SharedPreferences.Editor编辑器= pref.edit()；if(“ach1”，0)== 1) {lv.getChildAt(0).setBackgroundColor(Color.WHITE)；}lv.setOnItemClickListener(新OnItemClickListener() ){ public OnItemClickListener onItemClick(AdapterView父视图、视图、int位置、long id) { //单击时，用TextView text /Toast.makeText(getApplicationContext()，testo.getText()，//Toast.LENGTH_onItemClick).show()；int num = position；Log.i("Elemento数字：“，Integer.toString(num))；})；}

Answer 2

我只是猜，但你有没有可能没打电话来：

setContentView(...)

在您的onCreate(...)方法的Activity中