Android PagerAdapter IllegalStateException in FragmentActivity

Question

Ich bekomme den folgenden Fehler wie unten und ich kann nicht herausfinden, warum es auftritt. Ich habe keine weiteren Informationen über den Fehler.

Ich habe ein Android ListView mit 50 Elementen. Wenn Sie auf ein Element klicken und dann den zweiten Bildschirm (Fragment Activity with Pager) öffnen, werden in dieser Fragmentaktivität alle Elemente in einem Fragment von angeklicktem Element in der ListView bis zum letzten Element mit der Möglichkeit zum Streichen nach links oder rechts angezeigt.

java.lang.IllegalStateException: 
    at android.support.v4.view.ViewPager.populate(ViewPager.java:1167) 
    at android.support.v4.view.ViewPager.populate(ViewPager.java:1116) 
    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1642) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5797) 
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:436) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5797) 
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436) 
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:722) 
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5797) 
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:436) 
    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2910) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2048) 
    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1185) 
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1406) 
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1073) 
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5988) 
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767) 
    at android.view.Choreographer.doCallbacks(Choreographer.java:580) 
    at android.view.Choreographer.doFrame(Choreographer.java:550) 
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753) 
    at android.os.Handler.handleCallback(Handler.java:739) 
    at android.os.Handler.dispatchMessage(Handler.java:95) 
    at android.os.Looper.loop(Looper.java:135) 
    at android.app.ActivityThread.main(ActivityThread.java:5910) 
    at java.lang.reflect.Method.invoke(Native Method:0) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200) 

Answer 1

public class ScreenSlidePagerActivity extends FragmentActivity { 
    /** 
    * The number of pages (wizard steps) to show in this demo. 
    */ 
    public static int NUM_PAGES = 50; 

    /** 
    * The pager widget, which handles animation and allows swiping horizontally to access previous 
    * and next wizard steps. 
    */ 
    private ViewPager mPager; 

    /** 
    * The pager adapter, which provides the pages to the view pager widget. 
    */ 
    private PagerAdapter mPagerAdapter; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_screen_slide); 

     // Instantiate a ViewPager and a PagerAdapter. 
     mPager = (ViewPager) findViewById(R.id.pager); 
     mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager()); 
     mPager.setAdapter(mPagerAdapter); 

    } 

    @Override 
    public void onBackPressed() { 
     if (mPager.getCurrentItem() <= 0) { 

      //start an intent 
     } else { 
      // Otherwise, select the previous step. 
      mPager.setCurrentItem(mPager.getCurrentItem() - 1); 
     } 
    } 

    private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter { 
     public ScreenSlidePagerAdapter(FragmentManager fm) { 
      super(fm); 
     } 

     @Override 
     public Fragment getItem(int position) { 

      Bundle bundle = new Bundle(); 
      bundle.putSerializable("content", "bla bla content"); 

      MyFragment fragmentObj= new MyFragment(); 
      fragmentObj.setArguments(bundle); 
      return fragmentObj; 
     } 

     @Override 
     public int getCount() { 
      return NUM_PAGES; 
     } 

    } 


}