Nicht instanziieren Fragment stellen sicher, dass Klassenname existiert, ist öffentlich und hat einen leeren Konstruktor, der öffentlich ist

Question

Ich benutze das Fragment und wenn ich die Ausrichtung des Geräts ändern. Wenn zuerst sein Portrait und wenn ich es in Landschaft ändere, stürzt meine Anwendung ab. Ich habe den Logcat hier hinzugefügt. Ich habe viele Links durchgelesen, konnte aber nicht die richtige Antwort finden.

Bitte helfen Sie mir, dieses Problem zu lösen.

Dank

public class PageViewActivity extends FragmentActivity { 

    private ViewPager viewPager; 
    private NoticePageAdapter noticePageAdapter; 
    private TextView titleText; 
    private int pageIndex; 
    private static int restTime = 0; 
    private long lastTime; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     requestWindowFeature(Window.FEATURE_CUSTOM_TITLE); 
     setContentView(R.layout.activity_page_view); 

     getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.window_title2); 
     titleText = (TextView) findViewById(R.id.title2); 
     titleText.setText(R.string.app_name); 

     // Create the adapter that will return a fragment for each of the three 
     // primary sections of the app. 
     noticePageAdapter = new NoticePageAdapter(getSupportFragmentManager()); 

     // Set up the ViewPager with the sections adapter. 
     viewPager = (ViewPager) findViewById(R.id.viewpager); 
     Intent intent = getIntent(); 
     pageIndex = intent.getIntExtra("notice_position", 0); 
     viewPager.setAdapter(noticePageAdapter); 
     viewPager.setCurrentItem(pageIndex, true); 

     lastTime = System.currentTimeMillis(); 

     //Check the rest time. If it exceed the 30 sec then finish the activity. 
     new CheckTimeThread().start(); 
    } 

    /** 
    * A {@link FragmentPagerAdapter} that returns a fragment corresponding to 
    * one of the sections/tabs/pages. 
    */ 
    class NoticePageAdapter extends FragmentPagerAdapter { 

     public NoticePageAdapter(FragmentManager fm) { 
      super(fm); 
     } 

     @Override 
     public Fragment getItem(int position) { 
      Fragment fragment = new NoticeFragment(); 
      Bundle args = new Bundle(); 
      args.putInt(NoticeFragment.TEMPLATE_POSITION, position + 1); 
      fragment.setArguments(args); 
      return fragment; 
     } 

     @Override 
     public int getCount() { 
      return NoticeData.templateId.length; 
     } 
    } 

    /** 
    * A Notice fragment representing a notices of the app, but that simply 
    * displays notices 
    */ 
    public class NoticeFragment extends Fragment { 
     public static final String TEMPLATE_POSITION = "template_position"; 
     private TextView noticeHeaderTextView; 
     private TextView noticeContentTextView; 
     private ImageView noticeImageView; 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
      int templatePosition = getArguments().getInt(TEMPLATE_POSITION); 
      int templateId = 0; 
      int tempVar; 

      tempVar = templatePosition - 1; 
      templateId = Integer.parseInt(NoticeData.templateId[tempVar]); 

      int res = R.layout.first_template; 

      switch (templateId) { 
      case 1: 
       res = R.layout.first_template; 
       break; 
      case 2: 
       res = R.layout.second_template; 
       break; 
      case 3: 
       res = R.layout.third_template; 
       break; 
      case 4: 
       res = R.layout.fourth_template; 
       break; 
      default: 
       break; 
      } 

      View rootView = inflater.inflate(res, container, false); 
      noticeHeaderTextView = (TextView)rootView.findViewById(R.id.noticeHeading); 
      noticeHeaderTextView.setText(Html.fromHtml(NoticeData.noticeHeading[tempVar])); 

      noticeContentTextView = (TextView)rootView.findViewById(R.id.noticeContent); 
      noticeContentTextView.setText(Html.fromHtml(NoticeData.noticeContent[tempVar])); 

      noticeImageView = (ImageView)rootView.findViewById(R.id.noticeImageView); 
      UrlImageViewHelper.setUrlDrawable(noticeImageView, NoticeData.imagesURL[tempVar]); 

      DisplayMetrics metrics = getResources().getDisplayMetrics(); 
      int width = metrics.widthPixels; 

      if(templateId == 3) { 
       noticeImageView.getLayoutParams().width = width/2; 
      } 
      else if(templateId == 2) { 
       noticeHeaderTextView.getLayoutParams().width = width/2; 
       noticeContentTextView.getLayoutParams().width = width/2; 
      } 

      RelativeLayout relativeLayout = (RelativeLayout)rootView.findViewById(R.id.relativeLayout); 
      relativeLayout.setOnTouchListener(new OnTouchListener() { 
       @Override 
       public boolean onTouch(View v, MotionEvent event) { 
        resetRestTime(); 
        return false; 
       } 
      }); 

      return rootView; 
     } 
    } 
} 

Fehler Trace:

06-24 18:24:36.501: E/AndroidRuntime(11863): FATAL EXCEPTION: main 
06-24 18:24:36.501: E/AndroidRuntime(11863): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.noticeboard/com.noticeboard.PageViewActivity}: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.noticeboard.PageViewActivity$NoticeFragment: make sure class name exists, is public, and has an empty constructor that is public 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3365) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.access$700(ActivityThread.java:128) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1165) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.os.Handler.dispatchMessage(Handler.java:99) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.os.Looper.loop(Looper.java:137) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.main(ActivityThread.java:4514) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.reflect.Method.invokeNative(Native Method) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.reflect.Method.invoke(Method.java:511) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at dalvik.system.NativeStart.main(Native Method) 
06-24 18:24:36.501: E/AndroidRuntime(11863): Caused by: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.noticeboard.PageViewActivity$NoticeFragment: make sure class name exists, is public, and has an empty constructor that is public 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.Fragment.instantiate(Fragment.java:399) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.FragmentState.instantiate(Fragment.java:97) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1760) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:200) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at com.noticeboard.PageViewActivity.onCreate(PageViewActivity.java:40) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.Activity.performCreate(Activity.java:4465) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934) 
06-24 18:24:36.501: E/AndroidRuntime(11863): ... 12 more 
06-24 18:24:36.501: E/AndroidRuntime(11863): Caused by: java.lang.InstantiationException: can't instantiate class com.noticeboard.PageViewActivity$NoticeFragment; no empty constructor 
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.Class.newInstanceImpl(Native Method) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.Class.newInstance(Class.java:1319) 
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.Fragment.instantiate(Fragment.java:388) 
06-24 18:24:36.501: E/AndroidRuntime(11863): ... 19 more 

Answer 1

machte ich die innere Klasse zu statisch.

public static class NoticeFragment extends Fragment { 

Es löste mein Problem.

Answer 2

In getItem Funktion sollten Sie nicht Konstrukt-Funktion verwenden, um ein Fragment zu erstellen, sollten Sie newInstance Funktion verwenden.